Cancer is an important public health concern worldwide. GLOBOCAN 2012 reported that there were 14.1 million new cancer cases, 8.2 million cancer deaths, and 32.6 million people living with cancer (within 5 years of diagnosis) in 2012 worldwide. Traditional cancer treatments, such as surgery, chemotherapy, and radiotherapy, certainly affect the medical outcomes of cancer, but may not completely eradiate all types of cancers and always cause adverse effects. Therefore, enormous efforts are invested in exploring adjunctive interventions with minimal adverse effects in cancer patients.
Etiological studies have shown that genetic, environmental, and socioeconomic factors are only partly responsible for the development and prognosis of cancer. This has encouraged researchers to investigate the effect of psychological factors (PFs) on the initiation and prognosis of cancer. As a result, several studies have been published on the interactions between cancer and psychological factors such as chronic stress, anxiety, distress, depression, and psycho-social support. Although evidence of the positive influence of PFs in cancer survival is modest and findings are inconsistent, strong evidence has been obtained regarding the link between cancer progression and factors such as chronic stress, depression, and social isolation. According to Straub and Yan, PFs (stress, anxiety, depression) affect the tumor microenvironment (peripheral immune cells and inflammatory processes) via the hypothalamic–pituitary–adrenal axis, the sympathetic nervous system, and non-adrenal stress hormones, which may alter disease prognosis.[7,8]
Many randomized controlled trails have examined the relationship between PFs and the immune system in cancer.[9,10] Most of these trials have focused on the effect of psychological intervention (PI) on immune function. These PIs mainly include cognitive behavior therapy (CBT), stress management (SM), mind–body therapy (MT), and psychological support (PS), while the immune indicators mostly involved are the counts of immune cells, cytokines, and activity of NK cells. Although several meta-analyses have been conducted to collate the evidence regarding the effects of PI on immune response,[9,10] systematic analysis of the effects of different PIs at different stages in cancer treatment on immune function is generally lacking. In this study, we sought to analyze and compare the effect of various PIs administered at different stages of cancer treatment on immune response; we also aimed to evaluate the links between these changes and immune response of cancer patients and possibly their prognosis. We believe that our findings would provide some insights into the psychoneuroimmunology of cancer.
2.1 Inclusion and exclusion criteria
The protocol for the meta-analysis was developed in accordance with the PICOS approach. Studies were included in this analysis if they met the following criteria:
- 1. randomized controlled trials,
- 2. published in Chinese or English,
- 3. published before May 2018,
- 4. diagnosis of epithelial cancers established according to internationally accepted guidelines,
- 5. comparison of PI with usual care, and
- 6. outcomes recorded as post-treatment changes in immunological parameters.
Studies were excluded from the analysis if
- 1. they were not published in English or Chinese,
- 2. patients had any immunological or psychological diseases,
- 3. patients had received immune therapy for cancer or drugs for mental illness; and
- 4. the study design was other than randomized controlled trail.
The complete details about our study protocol are provided in the About pages at http://www.crd.york.ac.uk/ PROSPERO. The study is a meta-analysis which did not involve any interest of cancer patients, so the ethical review is not necessary.
2.2 Search strategy
A systematic computer-based literature search was conducted using relevant databases, including the Cochrane Library, EMBASE, PubMed, Web of Science, Chinese Biomedical Literature Database, Chinese Journal Full-Text Database, VIP Database, and Wanfang Database. We used the following search terms: “cancer” or “tumor” or “tumors” or “tumours” or “carcinoma” or “neoplasm” or “neoplasms” or “oncology” or “oncological”; and “psychological” or “psychology” or “emotion” or “psychotherapy”; and “recovery” or “reduce” or “therapy” or “ treatment” or “therapeutical” or “support” or “counsel”; and “immune” or “immunology”; and “immunological” and “random controlled trials” or “random.”
2.3 Study selection and data extraction
After eliminating duplicates using EndNote X7, the title, keywords, abstracts, and contents of all the articles retrieved were independently screened by two reviewers to check if they met the inclusion criteria. If there was any disagreement or doubt about potentially relevant articles, three reviewers jointly decided whether or not the study should be included in this review. Two independent reviewers extracted the data from each study, including authors, year of publication, type and stage of cancer, size of sample, mean patient age, intervention method, type of adjuvant treatment, duration of intervention, and immune outcome.
2.4 Data analysis/synthesis
We used Review Manager 5.3 (Cochrane Collaboration, Oxford, United Kingdom) for the meta-analysis. Since the parameters for the measurement of immune status were continuous data, the mean and standard deviation were used to collate the results of the studies. Heterogeneity was tested for all combined results by means of a Q statistic (calculated using a chi-square test), and inconsistency was calculated using an I2 index to determine the impact of heterogeneity. The presence of significant heterogeneity suggests diversity in the various characteristics of the studies, including stage of disease, age, diagnosis, gender, setting, intervention time, and type of assay. When the heterogeneity test was not statistically significant (I2 < 60%, P > .05), a fixed model was used; otherwise, a random effect model or subgroup analysis was used. However, when the heterogeneity of a subgroup analysis was still high (I2 > 60%, P < .05), the random effect model was used.
2.5 Literature quality analysis
Two independent reviewers assessed the internal validity of the studies using Cochrane Collaboration's tool (CCT) for assessing risk of bias Any disagreements were resolved by consultation with a third reviewer. The CCT is an effective instrument for the evaluation of the internal validity of randomized controlled trials. The quality of a study was classified as strong, moderate, or weak on the basis of the following six domains:
- 1. selection bias: random sequence generation and allocation concealment;
- 2. performance bias: blinding of participants and personnel;
- 3. detection bias: blinding of outcome assessment;
- 4. attrition bias: incomplete outcome data;
- 5. reporting bias: selective outcome reporting; and
- 6. other bias.
If the study was without bias, it was considered to be of high quality; if there was some literature bias, it was deemed to be of moderate quality; and if there was evidence of all types of bias, the study was classified as being of poor quality.
3.1 Study selection
After removal of duplicates using EndNote X7, and screened for title and their data abstracted by the inclusion criteria, 29 publications were finally included in this review (Fig. 1).
Study characteristics, publication bias, and quality of studies
Twenty-nine studies were included in the meta-analysis, including 17 English studies and 12 Chinese studies. In all studies, the cytokine concentrations were reported in picograms per milliliter (pg/mL). The type of intervention varied across the studies: 7 trails used cognitive behavior therapy; 4 utilized stress management; 8 employed mind-body therapy; and the remaining 10 trails adopted psychological supports. The trials also differed in terms of the cancer treatment period during which PI was administered. In four of the studies, patients received PI after completing therapy; in 6, during chemotherapy (CT); in 3, during radiotherapy (RT); in 12, during surgical treatment (ST); and in 4, during adjunctive (multiple) therapy. Among the included studies, 15 provided data on breast cancer. The characteristics of the 29 included studies are summarized in Table 1 .
Fifteen of these studies were of high quality, while 14 were of moderate quality. All the included studies reported random sequence generation using methods such as random numbers table, coin tossing, and dice throwing, and they provided complete data and results. Nine studies did not provide details regarding allocation concealment, while 14 studies did not provide a clear description about the blinding of the outcome assessment. Data on publication bias and quality of the studies included are detailed in Table 2.
3.2 Meta-analysis results
3.2.1 The effect of different PI approaches on immune cells
Compared with the control group, the SM group did not show any significant differences in CD3+ cell, CD4+ cell, and CD8+ cell counts; CD4+/CD8+ ratio; or NK cell count (P > .05), although significant changes were noted in the CBT group, MT group, and PS group (P < .05). Compared with MT and PS, the CBT group showed the highest magnitude of immune effect, and only the CBT group showed changes in NK cell activity (Table 3, Figs. 2–5).
3.2.2 The influence of PI on immune cells over various cancer treatment periods
Patients who received PI after cancer treatment completion or during CT did not exhibit changes in the counts of any immune indicators, as compared to the control group (P > .05). However, the counts of CD3+ cell, CD4+ cell, and CD8+ cell counts; CD4+/CD8+ ratio, and NK cell count of patients receiving PI during ST, RT, or adjunctive therapy were significantly different compared with the control group(P < .05, Table 4, Figs. 6–10)
3.2.3 The influence of PI on immune cells in breast cancer patients
Since many of the included studies focused on the effect of PI in breast cancer patients, we conducted a subgroup analysis for breast cancer patients. The CD3+ cell count, CD4+/CD8+ ratio, and NK cell count in breast cancer patients were significant higher in the PI group than in the control group (P > .05), but there were no differences in the CD4+ cell and CD8+ cell count between the two groups (P > .05, Table 5, Fig. 11).
3.2.4 The effect of PI on immune cytokines
Compared to patients not receiving PI, those who received PI had significantly higher serum levels of IL-2, IL-4, IFN-γ, lgA, and lgG. However, the differences in the serum levels of IL-6, IL-10, TNF-α, and IgM were not significant (P > .05, Fig. 12).
3.2.5 Meta-analysis of heterogeneity
Although we performed a subgroup meta-analysis according to the different PI methods employed, different stages of treatment during which PI was administered, and some of the cancer types, there still exist some heterogeneity. The source of heterogeneity may be attributed to sample size, intervention dosage, cancer stages, and patient characteristics.
4.1 Different immune effect of different PIs
Although there are many factors that affect cancer patient immunity, studies on psychoneuroimmunology (PNI) have proven that immunomodulation through stressors is a reliable and replicable phenomenon.[7,10] The results of our meta-analysis suggest that no significant immune changes were obtained through SM. To our knowledge, SM is an effective stress-reducing PI. However, the degree of cancer patient participation, compliance, and individual stress levels influences its efficacy; moreover, none of the studies that focused on SM took this point into consideration, and SM intervention showed no significant psychological effect as compared to control analogues.[12,13] To the best of our knowledge, the effect of PI on the immune response may be associated with improvements in psychological emotions, hypothalamic–pituitary–adrenal axis (HPA axis), and the sympathetic nervous system. The reason for the nonsignificant immune effect of SM might be the ineffective nature of the PI or low level of emotion distress.[14–16] The other PI-mediated immune responses may likely be attributed to psychological stress-reduction.[17,18] CBT appears to be the best therapeutic strategy for reducing stress and negative emotions. Working through stressful experiences can change a person's individual appraisal of subsequent stressors from a sense of threat to a sense of challenge. Perception of a potential stressor as a challenge may lead to changes and support improved immune function. Therefore, the magnitude of CBT influence on the immune response is greater than that of the other three PIs.
4.2 PI immune influence over cancer treatment progression
Because cancer patients might receive psychopharmacological treatment and anti-cancer therapy may affect immune cells, we conducted a subgroup analysis on various therapies. Our meta-analysis revealed that PI intervention changed the concentration of T and NK cells in cancer patients when administered during ST, RT, and adjunctive therapy (P < .05), but not after completion of the cancer treatment (P > .05). There were no significant differences in the activity levels of the NK cells between the PI group in the chemotherapy and the control groups. We believe that cancer treatment may affect the concentration of immune cells. Lengacher et al showed that compared to T cells, NK cells were more susceptible to suppression during cancer treatment. However, studies still indicate that PI can result in changes in the levels of some immune indicators in cancer patients during different treatment periods.[12,13,15,17,20] Wang et al have shown that NK cell activity is associated with the severity of anxiety and depression in cancer patients and that the degree of psychological recovery might affect NK cell activity.[21,22] However, studies on PI during chemotherapy did not indicate any psychological changes after intervention.[22,23] The lack of significant changes in NK cell activity during CT may be due to unclear psychological PI or immunosuppression effects caused by CT.
4.3 The Immune response to PI in breast cancer patients
Our meta-analysis consistently showed that PI can change the CD3+ cell count, CD4+/CD8+ratio, and NK cells in breast cancer patients (P < .05), but not the CD4+ cell and CD8+cell counts (P > .05). CD3+ cells could positively promote and enhance the immune response. When the concentrations of CD3+ cells and CD4+/CD8+ increase in breast cancer patients, relapse or metastasis may occur, leading to poor prognoses. Therefore, PI may be beneficial to the prognosis of breast cancer patients.
4.4 Post-PI influence on immune indicator levels and/or activity and ultimate cancer prognosis.
With respect to the immune response trends, we found that there was an increase or decrease in the T-cells counts, but consistent increases in the NK cell count and activity were observed (P < .05). Four of the 10 studies on NK cells confirmed that PI can improve the NK cell content in cancer patients. Likewise, the overall meta-analysis revealed an increase in NK cell count. Three of five studies on NK cell activity indicated that PI may promote the activity of these cells and the overall meta-analysis revealed an increase in NK cell activity. NK cells, which are members of the innate immune cells family, are the first line of defence against tumors and infection, assuming the function of immune surveillance cancer cells direct killing. NK cell activity can control the growth and spread of pathogens and tumors, both of which play an active immune-monitoring role in controlling the occurrence and metastasis of primary tumors. The concentration and activity of NK cells in cancer patients are generally low; however, increases in their numbers have a positive influence in terms of enhancing immune surveillance and tumor occurrence prevention, and metastasis. Therefore, increases in NK cell count and NK cell activity could have a positive influence on the immune function and, ultimately the prognosis of cancer patients.
Three of the five studies on IL-2 showed that PI can increase IL-2 concentration and the overall meta-analysis revealed an increase in IL-2 levels. Two of the four studies on IL-4 confirmed that IL-4 content increased significantly after PI and the overall meta-analysis showed an increase in the IL-2 level. Three of the six studies on IFN-γ proved that PI can increase IFN-γ levels, and the overall meta-analysis revealed an increase in the level of IFN-γ. IL-2 and IFN-γ can significantly induce NK cells to produce and enhance antitumor activity, and low concentration of these cells in cervical cancer has been shown to predict severe disease. IL-4 has the effect of inhibiting the growth of breast tumors. Therefore, the increase in the content of IL-2, IL-4, and IFN-γ may have a positive effect on the immune function and prognosis of cancer patients. Two of the three studies on immunoglobulins confirmed that PI could increase the content of IgA and IgG. The immunoglobulin content reduces in patients with worsening, progressive cancer, and poor prognosis. The increase in the concentrations of immunoglobulins may have some beneficial effect in the prognosis of cancer patients.
Further investigations are necessary to determine the mechanism and stability of the immune effect of PI.
Recent studies show that the immune effect of PI may be related to the neuroendocrine changes caused by cognitive changes and improvement in the patient's psychological state.[33–35] However, our subgroup meta-analysis revealed that SM and PI administered after the completion of the cancer therapy or during CT did not bring about any change in the levels of the immune indicators in cancer patients. The stability of the immune effect of PI may also be influenced by intervention-related factors such as PI duration time,[9,10] content of PI,[12,31] and effect of PI as well as the cancer stage, the type of adjuvant treatment, the severity of psychological stress disorder,[14–16,33] the degree of PI participation, and ability for recovery from immunosuppression. There is also some evidence on the interactions between PI and immune indicators, but the psychoneuroimmunology mechanism underpinning the influence of PI on the immune system still remains unclear and further investigations are necessary to elucidate these.
This study has some limitations. Most of the papers retrieved by our search were of moderate quality, and most of the enrolled cancer patients in the included studies were female. Furthermore, due to the lack of studies focusing on similar patient groups, subgroup analyses based on the duration of PI or immune function indicators could not be performed in this study. Another point worth mentioning is that the plausible ability of cancer cells evading detection by the immune system makes it difficult to conclusively define the benefits of PI on an individual's immune response.
There is some evidence that supports the benefits of PI on some immune indicators and these immune changes benefit the overall immune function in cancer patients, and possibly their prognosis. However, the definitive influence of PI remains vague and cannot be conclusively defined in terms of immune function and prognosis in cancer patients. Moreover, further research is necessary to examine the individual influence of various PI types against different cancer treatments.
We gratefully acknowledge Ping Zhang, Xia Li, and Qiyao Wang for the literature search, screen, data extract and data analysis. Ping Zhang was a major contributor to the writing of the manuscript and Professor Mo checked the manuscript.
Conceptualization: Xia Li, Qiyao Wang.
Data curation: Ping Zhang, Xia Li, Qiyao Wang.
Formal analysis: Ping Zhang, Xia Li, Qiyao Wang.
Investigation: Ping Zhang, Xia Li, Qiyao Wang.
Writing – original draft: Ping Zhang.
Writing – review & editing: Mo Lin.
. Ferlay J, Soerjomataram I, Dikshit R, et al. Cancer incidence and mortality worldwide: sources, methods and major patterns in GLOBOCAN 2012. Int J Cancer 2015;136:E359–386.
. Jassim GA, Whitford DL, Hickey A, et al. Psychological interventions for women with non-metastatic breast cancer. Cochrane Database Syst Rev 2015;CD008729.
. Bertone-Johnson ER. Epidemiology of ovarian cancer: a status report. Lancet 2005;365:101–2.
. Pruneti CA, Cosentino C. Integrative Cancer Science and Therapeutics Towards an integrated model of defense in gynecological cancer. Psychoneuroimmunological and psychological factors, between risk and protection in cancer: a review. Integ Cancer Ther 2015;2:112–7.
. Witek-Janusek L, Gabram S, Mathews HL. Psychologic stress, reduced NK cell activity, and cytokine dysregulation in women experiencing diagnostic breast biopsy. Psychoneuroendocrinology 2007;32:22–35.
. Ben-Eliyahu S, Page GG, Schleifer SJ. Stress, NK cells, and cancer: still a promissory note. Brain Behav Immun 2007;21:881–7.
. Qing Y. Biological rhythms and the HPA axis in psychoneuroimmunology. Psychoneuroimmunology 2016;19–26.
. Straub RH, Cutolo M. Psychoneuroimmunology-developments in stress research. Wien Med Wochenschr 2018;168:76–84.
. Newell SA, Sanson-Fisher RW, Savolainen NJ. Systematic review of psychological therapies for cancer patients: overview and recommendations for future research. J Natl Cancer Inst 2002;94:558–84.
. Tong G, Geng Q, Cheng J, et al. Effects of psycho-behavioral interventions on immune functioning in cancer patients: a systematic review. J Cancer Res Clin Oncol 2014;140:15–33.
. Jorgensen L, Paludan-Muller AS, Laursen DR, et al. Evaluation of the Cochrane tool for assessing risk of bias in randomized clinical trials: overview of published comments and analysis of user practice in Cochrane and non-Cochrane reviews. Syst Rev 2016;5:80.
. Lengacher CA, Bennett MP, Gonzalez L, et al. Immune responses to guided imagery during breast cancer treatment. Biol Res Nurs 2008;9:205–14.
. Reich RR, Lengacher CA, Kip KE, et al. Baseline immune biomarkers as predictors of MBSR(BC) treatment success in off-treatment breast cancer patients. Biol Res Nurs 2014;16:429–37.
. Lindemalm C, Mozaffari F, Choudhury A, et al. Immune response, depression and fatigue in relation to support intervention in mammary cancer patients. Support Care Cancer 2008;16:57–65.
. McGregor BA, Antoni MH, Boyers A, et al. Cognitive-behavioral stress management increases benefit finding and immune function among women with early-stage breast cancer. J Psychosom Res 2004;56:1–8.
. Ross L, Frederiksen K, Boesen SH, et al. No effect on survival of home psychosocial intervention in a randomized study of Danish colorectal cancer patients. Psychooncology 2009;18:875–85.
. Baker BS, Harrington JE, Choi BS, et al. A randomised controlled pilot feasibility study of the physical and psychological effects of an integrated support programme in breast cancer. Complement Ther Clin Pract 2012;18:182–9.
. van der Pompe G, Antoni MH, Duivenvoorden HJ, et al. An exploratory study into the effect of group psychotherapy on cardiovascular and immunoreactivity to acute stress in breast cancer patients. Psychother Psychosom 2001;70:307–18.
. Buhle JT, Silvers JA, Wager TD, et al. Cognitive reappraisal of emotion: a meta-analysis of human neuroimaging studies. Cereb Cortex 2014;24:2981–90.
. Cohen L, Parker PA, Vence L, et al. Presurgical stress management improves postoperative immune function in men with prostate cancer undergoing radical prostatectomy. Psychosom Med 2011;73:218–25.
. Kang DH, McArdle T, Park NJ, et al. Dose effects of relaxation practice on immune responses in women newly diagnosed with breast cancer: an exploratory study. Oncol Nurs Forum 2011;38:E240–252.
. Wang JP, Lin WJ. Effects of psychological intervention on immunological function in cancer patients. Chin J Oncol 2002;29:841–4.
. Lekander M, Furst CJ, Rotstein S, et al. Immune effects of relaxation during chemotherapy for ovarian cancer. Psychother Psychosom 1997;66:185–91.
. Song ZY. Detection of peripheral blood T lymphocyte subsets and immunoglobulin in monitoring and prognosis evaluation of gastric cancer. Pract J Cancer 2015;30:1126–8.
. Carrega P, Bonaccorsi I, Di Carlo E, et al. CD56(bright)perforin(low) noncytotoxic human NK cells are abundant in both healthy and neoplastic solid tissues and recirculate to secondary lymphoid organs via afferent lymph. J Immunol 2014;192:3805–15.
. Gras Navarro A, Bjorklund AT, Chekenya M. Therapeutic potential and challenges of natural killer cells in treatment of solid tumors. Front Immunol 2015;6:202.
. Lee SB, Cha J, Kim IK, et al. A high-throughput assay of NK cell activity in whole blood and its clinical application. Biochem Biophys Res Commun 2014;445:584–90.
. Mathai AM, Kapadia MJ, Alexander J, et al. Role of Foxp3-positive tumor-infiltrating lymphocytes in the histologic features and clinical outcomes of hepatocellular carcinoma. Am J Surg Pathol 2012;36:980–6.
. Liu XL, Hao TT, Li YX. Th1/Th2 cells and tumor microenvironment. Chin Practi J Cancer 2015;30:1415–7.
. Thakur A, Schalk D, Sarkar SH, et al. A Th1 cytokine-enriched microenvironment enhances tumor killing by activated T cells armed with bispecific antibodies and inhibits the development of myeloid-derived suppressor cells. Cancer Immunol Immunother 2012;61:497–509.
. Antoni MH, Lechner S, Diaz A, et al. Cognitive behavioral stress management effects on psychosocial and physiological adaptation in women undergoing treatment for breast cancer. Brain Behav Immun 2009;23:580–91.
. Shuang JQ, Wu T, Zhuang ZH. The effect of NS398 on the growth of SGC7901 gastric cancer cell and MMP-9 gene expression. Chin Pract J Cancer 2013;28:15–9.
. Andersen BL, Farrar WB, Golden-Kreutz DM, et al. Psychological, behavioral, and immune changes after a psychological intervention: a clinical trial. J Clin Oncol 2004;22:3570–80.
. Savard J, Simard S, Ivers H, et al. Randomized study on the efficacy of cognitive-behavioral therapy for insomnia secondary to breast cancer, part II: immunologic effects. J Clin Oncol 2005;23:6097–106.
. Shen Q, Yang WX, Zhu L. The effect of foreseeable psychological intervention on negative emotion and immune function of patients with lung cancer chemotherapy. Modern J Integ Trad Chin West Med 2017;26:1129–31.
. Bower JE, Crosswell AD, Stanton AL, et al. Mindfulness meditation for younger breast cancer survivors: a randomized controlled trial. Cancer 2015;121:1231–40.
. Robins JL, McCain NL, Elswick RK Jr, et al. Psychoneuroimmunology-based stress management during adjuvant chemotherapy for early breast cancer. Evid Based Complement Alternat Med 2013;2013:372908.
. Cho EA, Oh HE. Effects of laughter therapy on depression, quality of life, resilience and immune responses in breast cancer survivors. J Korean Acad Nurs 2011;41:285–93.
. Eremin O, Walker MB, Simpson E, et al. Immuno-modulatory effects of relaxation training and guided imagery in women with locally advanced breast cancer undergoing multimodality therapy: a randomised controlled trial. Breast 2009;18:17–25.
. Zhou LM. Effect of cognitive nursing on negative emotion and immune function of cervical carcinoma. J Cardiovas Prevent Control 2017;1:89–189.
. Dong Y, Zhang YM, Wu QX. Impacts of psychological intervention on anxiety-depression emotions,coping styles and immune function of cancer patients undergoing radiotherapy. J Clin psychosom Dis 2016;22:69–72.
. Li J, Xu R, Wu XL. Effect of psychosocial treatment on anxiety or depression status and immune function in patients with gastric cancer. J Chin Oncol 2016;22:722–6.
. Ren JB, Jia WJ, Ni YM. Effect of focusing on solving model on anxiety status, depression status,chemotherapy compliance and immunological function in patients with cancer. Chin J Clin Oncol Rehabil 2015;22:743–6.
. Peng L, Xie JD, Hu Y. Impact of cognitive behavioral therapy on immune and emotion function of non-small Cell lung cancer patients. Mod Oncol 2015;23:2953–6.
. Zheng X, You ZB, Tian WZ. Effect of all in one nursing intervention on patients with anxiety and depression of esophageal carcinoma negative emotion and immune function. Chin J Prac Nurs 2015;31:1994–8.
. Guo YJ. Effect of individualized psychological intervention on psychological status and immune function of rectal cancer during perioperative period. Chin J Mod Nurs 2015;21:2680–2.
. Chen XF, Fang ZH. Influence of psychological nursing intervention on serum cytokine of breast cancer patients treated with postoperative chemotherapy. China Modern Doctor 2013;51:129–33.
. Han RY, Wang AJ, Zhang DJ. Effect of cognitive intervention on emotion and immune function of peri operative period cervical carcinoma. Acad J Chinese PLA Med Sch 2013;34:371–2.