Treating More Women, Elderly Could Improve Colon Cancer Survival

WASHINGTON-Adjuvant chemotherapy has improved survival in stage III colon cancer, but to make any further progress, more women and older patients should receive treatment, John M. Jessup, MD, told ONI. Although more women and older patients are receiving adjuvant therapy than in the past, they are still not receiving as much treatment as male patients and younger patients, he emphasized, in discussing results of a study including more than 150,000 patients treated between 1985 and 2001 (abstract 3533). "Our real message is that it would make sense to once again reinvigorate the use of adjuvant therapy," said Dr. Jessup, professor of oncology at Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC. "In this country, women do not get chemotherapy as often as men... and many older folks do not get che- motherapy as you would expect." In the last decade, he noted, adjuvant chemotherapy use has actually increased and is now a standard of practice, following a 1990 National Institutes of Health consensus conference that recommended it for stage III colon cancer. To determine whether this shift has in fact improved survival, Dr. Jessup and colleagues queried the National Cancer Data Base (NCDB), a project of the American College of Surgeons' Commission on Cancer. The study included 156,240 pa tients with stage III colon cancer who were treated in 1,902 hospitals and entered prospectively into the database between 1985 and 2001. Investigators performed a standard statistical analysis to determine associations between 5-year relative survival and a variety of clinical, demographic, and treatment variables. As expected, adjuvant chemotherapy use was found to increase in the NCDB population, from 9.5% in 1985, to 52.2% in 1991, to 63% in 2001. Survival in patients treated by surgery alone was 48.7% in 1991; adding adjuvant chemotherapy improved survival by about 10%. In 1996, survival was 53.4% for surgery alone and about 17% higher for patients who also received adjuvant chemotherapy. Deficit Remains
Adjuvant chemotherapy use did increase in women and the elderly over time, but there is still a deficit on both counts, data show. Still today, more women do not receive chemotherapy; in 2000-2001, about 11% of men had surgery only, compared with 15% of women. Likewise, less than 40% of patients over 80 years of age receive adjuvant treatment. "If you wanted to improve outcomes, you would treat more women and older people," Dr. Jessup said. Similar Benefits, No Increased Toxicity
In particular, he cited a study by Mayo Clinic researchers who performed a pooled analysis of adjuvant chemotherapy for resected colon can- cer in elderly patients (N Engl J Med 345:1091-1097, 2001). They found that, compared with younger counterparts, elderly patients with stage II/ III colon cancer appear to receive a similar benefit from fluorouracil(Drug information on fluorouracil) (5- FU)-based adjuvant chemotherapy, with no significant increase in toxic effects. The Mayo Clinic pooled analysis included data on 3,351 elderly patients in seven phase III randomized trials comparing surgery alone vs surgery plus fluorouracil-based chemotherapy. Five-year overall survival was 71% for elderly patients who received adjuvant therapy, compared with 64% of untreated patients. Except for increased leukopenia, there was no increase in the incidence of toxic effects. Interestingly, Dr. Jessup noted that the NCDB analysis also found that while differentiation and T stage were similar over time, N2 nodes increased from 28.3% in 1991 to 31.3% in 2001 (P < .0001). "We're not sure why," he said. "It may be that pathologists are counting the number of positive nodes more accurately."