Treating More Women, Elderly Could Improve Colon Cancer Survival

WASHINGTON-Adjuvantchemotherapy has improved survivalin stage III colon cancer, but to makeany further progress, more women andolder patients should receive treatment,John M. Jessup, MD, told ONI.Although more women and older patientsare receiving adjuvant therapythan in the past, they are still not receivingas much treatment as malepatients and younger patients, he emphasized,in discussing results of astudy including more than 150,000patients treated between 1985 and 2001(abstract 3533)."Our real message is that it wouldmake sense to once again reinvigoratethe use of adjuvant therapy," said Dr.Jessup, professor of oncology at LombardiComprehensive Cancer Center,Georgetown University, Washington,DC. "In this country, women do notget chemotherapy as often as men...and many older folks do not get che-motherapy as you would expect."In the last decade, he noted, adjuvantchemotherapy use has actuallyincreased and is now a standard ofpractice, following a 1990 NationalInstitutes of Health consensus conferencethat recommended it for stage IIIcolon cancer. To determine whetherthis shift has in fact improved survival,Dr. Jessup and colleagues queried theNational Cancer Data Base (NCDB), aproject of the American College ofSurgeons' Commission on Cancer.The study included 156,240 patients with stage III colon cancer whowere treated in 1,902 hospitals andentered prospectively into the databasebetween 1985 and 2001. Investigatorsperformed a standard statisticalanalysis to determine associationsbetween 5-year relative survival and avariety of clinical, demographic, andtreatment variables.As expected, adjuvant chemotherapyuse was found to increase in theNCDB population, from 9.5% in 1985,to 52.2% in 1991, to 63% in 2001.Survival in patients treated by surgeryalone was 48.7% in 1991; adding adjuvantchemotherapy improved survivalby about 10%. In 1996, survival was53.4% for surgery alone and about17% higher for patients who also receivedadjuvant chemotherapy.Deficit Remains
Adjuvant chemotherapy use did increasein women and the elderly overtime, but there is still a deficit on bothcounts, data show. Still today, morewomen do not receive chemotherapy;in 2000-2001, about 11% of men hadsurgery only, compared with 15% ofwomen. Likewise, less than 40% ofpatients over 80 years of age receiveadjuvant treatment."If you wanted to improve outcomes,you would treat more womenand older people," Dr. Jessup said.Similar Benefits,No Increased Toxicity
In particular, he cited a study byMayo Clinic researchers who performeda pooled analysis of adjuvantchemotherapy for resected colon can-cer in elderly patients (N Engl J Med345:1091-1097, 2001). They foundthat, compared with younger counterparts,elderly patients with stage II/III colon cancer appear to receive asimilar benefit from fluorouracil (5-FU)-based adjuvant chemotherapy,with no significant increase in toxiceffects.The Mayo Clinic pooled analysisincluded data on 3,351 elderly patientsin seven phase III randomized trialscomparing surgery alone vs surgeryplus fluorouracil-based chemotherapy.Five-year overall survival was 71%for elderly patients who received adjuvanttherapy, compared with 64% ofuntreated patients. Except for increasedleukopenia, there was no increasein the incidence of toxic effects.Interestingly, Dr. Jessup noted thatthe NCDB analysis also found thatwhile differentiation and T stage weresimilar over time, N2 nodes increasedfrom 28.3% in 1991 to 31.3% in 2001(P < .0001). "We're not sure why," hesaid. "It may be that pathologists arecounting the number of positive nodesmore accurately."