Research is continuing on ways to minimize the long-term pain that often plagues breast cancer survivors. A recent study by Danish researchers found that 47% of 3,253 women surveyed felt pain around their breast two to three years after surgery. Half of them reported their pain as moderate to severe, and 5% had sensory problems. Other recent studies have yielded similar results, with chronic-pain rates of 25% to 50% and numbness rates of 20% to 80%.
“As we get better at keeping people alive from cancer, we need to focus on what we can do to improve their lives,” said Lee Wilke, MD, a breast cancer surgeon at Duke University School of Medicine.
A closer look at the Danish data, a study led by Rune Gärtner, MD, of the University of Copenhagen and published in the Journal of the American Medical Association (2009;302:2034-2035), suggests that at least some patients can have improvement in their quality of life. Their pain appears linked to their age and lifestyle or the type of treatment they received. By identifying patients at greatest risk, clinicians hope to minimize long-term pain.
“Patients at high risk for the development of post-surgical pain should have therapy initiated early, and the effects of early intervention should be assessed,” Loretta Loftus, MD, and Christine Laronga, MD, wrote in an accompanying editorial. Both are breast cancer specialists at H. Lee Moffitt Cancer Center & Research Institute.
The number one risk factor the Danish researchers found is youth. Among patients under 40, 64% reported pain. The rate dropped to 59% in women 40 to 49, 49% in those 50 to 59, and 41% in those 60 to 69.
The reason for the difference is not clear, but may be related to lifestyle: “Younger people are more active, and pain could be related to their activity,” said Lisa Jacobs, MD, Assistant Professor of Surgery at Johns Hopkins University School of Medicine.
Dr. Loftus noted that older women, on the other hand, may have a higher tolerance to pain.
Another Danish study found that single women and those with less education reported more pain than married, highly educated women.
“Single women may have less emotional support,” Dr. Loftus said. “They may be depressed, which can affect perceptions of pain. Pain is a complex issue. It may cause emotional distress that could indirectly impact pain perception.”
She said it's not surprising that the women in the Danish study most likely to report long-term breast pain also had a high incidence of reporting unrelated pain in other parts of their bodies.
Radiotherapy Increases Risk
While nothing can be changed about a patients' age or marital status, other factors affecting long-term pain may be amenable to change—for example, radiotherapy. Patients treated with radiation generally experienced more pain than those who did not have radiation therapy. And pain was more severe in radiotherapy patients who had undergone mastectomy than those who had breast-conserving surgery.
“When you combine radiation with surgery, the number of complications will go up,” said Anthony Lucci, MD, Associate Professor of Surgical Oncology at the University of Texas M. D. Anderson Cancer Center.
One way radiation increases pain, Dr. Lucci explained, is by thickening scar tissue. Another is by promoting lymphedema.
Dr. Lucci raised the question of whether women with minimal or no lymph-node cancer would fare better without radiotherapy: “We need to be selective about whom we offer radiation to, and make sure that there is a significant benefit.”
Dr. Wilke agrees: “If we can reduce the amount of radiation, we'd like to.”
That idea, though, is fraught with controversy. A 2005 analysis of 78 clinical trials, published in The Lancet, supports the value of radiotherapy in women with early-stage breast cancer. The study showed that women treated with radiotherapy had a 19% reduction in recurrence five years later compared with women treated with surgery alone. That's enough evidence for many oncologists to recommend radiation for early- as well as later-stage patients. But the study also showed an increase in secondary cancers and deaths from heart disease and lung cancer in the radiation- treated group.
A compromise for women who have had breast-conserving surgery is partial-breast irradiation (PBI). The method is appealing because it cuts treatment from six or seven weeks to five to 10 days. Targeted radiation may be administered externally, like whole-breast irradiation, or internally, through a removable catheter inserted during surgery.
At the most recent ASCO Annual Meeting, David Mauri, MD, of General Hospital of Lamia in Greece, presented a meta-analysis showing no significant difference in survival between women who had partial- and whole-breast irradiation. Dr. Mauri did express concern about a higher rate of local and regional recurrence in PBI patients. Also at the meeting, a team of UK and Australian researchers reported a study showing that the appearance of breasts treated with intraoperative radiotherapy was comparable to those treated postsurgically with external radiation.
“I think they'll eventually be considered equivalent,” Dr. Jacobs said of internal and external radiotherapy. As of yet, she added, “There's no evidence it would improve breast pain.”
PBI is not an option for mastectomy patients. For those with little or no node involvement, Dr. Lucci suggests minimizing the risk of long-term pain and other complications by forgoing radiotherapy altogether. M. D. Anderson is now comparing outcomes in early-stage mastectomy patients who did and did not undergo radiotherapy.
Some of the M. D. Anderson research has shown promising results in patients who had no radiotherapy, but underwent neoadjuvant chemotherapy. The Danish researchers found no link between chemotherapy and long-term pain.
Node Dissection Linked to Numbness
Another potential approach to minimizing pain is reducing the rate of axillary lymph-node dissection.
“It's the number one thing that causes pain and problems,” Dr. Lucci said. “We should minimize the amount of axillary-node removal whenever possible.”
Dissection raises the risk of chronic pain and numbness because it often injures the intercostal-brachial nerves. The standard of care is to excise one or two sentinel nodes for biopsy, and remove the axillary nodes only if the sentinel ones are positive. But older surgeons practicing in rural areas may not be trained in the sentinel-node technique.
“We see more axillary dissections and fewer sentinel-node attempts in the community, but that's changing,” Dr. Loftus said. “More residents are trained to do sentinel node.”
While researchers weigh the pros and cons of pain-sparing treatments, clinicians can take steps to relieve survivors' pain.
“Pain is a common problem,” Dr. Loftus said. “Patients should be asked about it. An evaluation should be made to determine the cause.”
In their editorial, Drs. Loftus and Laronga recommend a multidisciplinary approach to pain enlisting oncologists, surgeons, pain-management specialists, psychologists, and physical therapists.
Patients often use alternative treatments in additional to medication. These may include acupuncture to treat pain, massage to soften scar tissue and relieve lymphedema, and yoga for relaxation. Little is known about which treatments work best. Maybe it's time someone finds out, Dr. Wilke suggests: “We need to study it in a more rigorous fashion.”