In a situation that is contrary to current guidelines, it is possible that a select group of patients with advanced-stage, incurable cancer can benefit from home total parenteral nutrition (TPN), researchers report.
The number of such patients is quite small and for most, TPN is initiated due to weight loss caused by mechanical gastrointestinal problems, not anorexia, Aminah Jatoi, MD, Associate Professor of Oncology at the Mayo Clinic, and her colleagues found. Nevertheless, home TPN can be associated with long-term survival in these patients.
“A number of organizations in the United States, including the American College of Physicians, advise against the routine use of parenteral nutrition in patients with incurable cancer, and we accept that,” Dr. Jatoi said in an interview.
“Our study was an attempt to say, every now and then there is a patient who is different and maybe needs a different approach. What we found is a very small subset that does benefit. However, the judicious use of home total parenteral nutrition requires a careful clinical assessment on a case-by-case basis.”
Writing in a recent issue of Cancer (2005;103:863–868), Dr. Jatoi and colleagues reported that 16 of 52 patients in their retrospective series survived for at least one year from initiation of home total parenteral nutrition, with one patient still receiving it 12 years later.
The complication rate was acceptable, with 18 catheter infections, four thromboses, three pneumothoraces, and two episodes of TPN-related liver disease, they reported.
Aminah Jatoi, MD: “A number of organizations in the US, including the American College of Physicians, advise against the routine use of parenteral nutrition in patients with incurable cancer, and we accept that. Our study was an attempt to say, every now and then there is a patient who is different and maybe needs a different approach.”
The study represents the largest retrospective series of patients with metastatic, incurable cancer who received total parenteral nutrition, Dr. Jatoi said.
Obstruction, Malabsorption Common Reasons for Weight Loss
For the study, the researchers combed though the records of all adult patients with incurable cancer treated at the Mayo Clinic between 1979 and 1999 and identified 52 patients who had received home TPN. The median age of the patients, 58% of whom were women, was 56.
Ten of the 52 patients suffered from carcinoid or islet cell tumors, making that the most common cancer among patients receiving home TPN.
Six patients suffered from ovarian carcinoma, six from amyloidosis or multiple myeloma, five from colorectal carcinoma, five from sarcoma, four from pancreatic carcinoma, three from gastric carcinoma, two each from lymphoma and pseudomyxoma peritonei, and nine from a variety of other tumor types.
Nearly three-fourths of the patients lost 4.5 kg or more before the initiation of TPN, and the weight loss was caused by mechanical gastrointestinal problems in the majority of patients.
Specifically, the most common reasons for the initiation of TPN were obstruction of the alimentary tract, observed in 20 patients, and short bowel syndrome or malabsorption, seen in 16 patients.
Only two patients started TPN due to anorexia, which is typically the cardinal cause of weight loss in incurable cancer patients, Dr. Jatoi noted.
The median time from the initiation of TPN to death was five months, with 16 patients surviving at least a year.
The tumor grade, the interval between diagnosis of metastatic disease and initiation of TPN, the presence of prominent cancer symptoms, and the administration of cancer therapy after TPN were not associated in any way with overall survival, the study showed.
Only two patients stopped TPN because of complications. “All we can say is that those who got home TPN were different in that they tended to have rare tumors and tended to suffer weight loss due to obstruction or malabsorption. But we can't even say which of these patients then benefited,” Dr. Jatoi said.
Nevertheless, “the study shows that some patients who receive TPN, even in the setting of metastatic, incurable cancer, can live well beyond a few months.
“Because cessation of energy intake is associated with a life expectancy of only a few months, the long-term survivors in our series suggest that TPN can be a lifesaving and life-sustaining intervention for some patients with incurable cancer.”
Clinical Judgment Crucial
So how does an oncologist know if his or her patient is one of the few who will benefit?
“Instinct and experience,” Dr. Jatoi said. “Clinical judgment seems to play the biggest role in helping to understand who might benefit.”
Noting that TPN can be cumbersome, she said, “We have to be careful that home TPN will not be a burden to the patient. Despite suffering incurable cancers, many patients are going about business as usual. You have to choose patients who will really be helped.”
Some patients only need nighttime feedings, which eases the burden, Dr. Jatoi said.
She also stressed that the option must be discussed with the patient, family members, and other health care staff. “The patient and family really need to know what they're getting into, the central line, the bag, everything. All should agree this is a patient for whom ‘breaking the rules’ is a good idea,” she said.
The most common reason for initiating TPN was mechanical bowel obstruction. Only two patients had anorexia, which is typically the cardinal cause of weight loss in incurable cancer patients.
Michael H. Levy, MD, PhD, Director of Supportive Care and Vice-Chair of the Department of Medical Oncology at Fox Chase Cancer Center, agreed.
“There needs to be multidisciplinary discussion, also discussions with the family and patient. It's very important to go over all the risks and benefits and set realistic goals.”
Also, time limits should be set, he said. “Just as with chemotherapy, you should try [home TPN] for a set amount of time—in this case, a week or two—and see how it goes. If the patient is developing a lot of infections and the body can't use the nutrition but the tumor can, some think the tumor will grow faster.”
Some Words of Caution
What the study seems to suggest, he said, is that the patients who are most likely to benefit are those with mechanical bowel obstruction and those who suffer from cancers, such as ovarian cancer, that usually do not spread to vital organs.
Overall, however, “there should not be a rush by patients or clinicians to start doing this,” Dr. Levy said.
For starters, the retrospective study doesn't answer the question of whether home TPN extends lives, he said. “I don't know if survival would have been any different if they had just been given intravenous fluids.”
Then, there are the issues of quality of life and cost, both of which were beyond the scope of this study, Dr. Levy said.
“The study provides good background for a randomized clinical trial in which half of the patients get TPN and half get IV fluids. We can measure quality of life and economic issues and see whether there really is benefit.
“Then it ultimately becomes an issue of whether insurance and society are willing to pay.”