Trends in stage distribution and survival among elderly colorectal cancer patients in the U.S.

Abstract

4043 Background: Advances in colorectal cancer (CRC) screening and treatment have occurred over the past decade. This study used nationally representative data to examine trends in stage distribution and survival. Methods: Using SEER data from the National Cancer Institute, we identified patients newly diagnosed with adenocarcinoma of the colon (CC) or rectum (RC) from 1988–2003 and analyzed trends in stage distribution. Observed Kaplan-Meier survival was evaluated by cancer site, stage, and diagnosis year. Results: We identified 174,038 patients with de novo CRC diagnosed in 1988–2003 (75% with colon cancer). In 1988, 2% of CC patients were diagnosed at Stage 0, 19% at Stage 1, 33% at Stage 2, 21% at Stage 3, and 17% at Stage 4 (the remainder were unstaged). The corresponding distribution in 2003 was 2%, 23%, 30%, 23%, and 16% at Stages 0–4, respectively, showing no difference in the share of patients diagnosed at Stage 0, more patients now diagnosed in Stages 1 and 3 and fewer in Stages 2 and 4. In 1988, 2% of RC patients were diagnosed at Stage 0, 31% at Stage 1, 24% at Stage 2, 18% at Stage 3, and 15% at Stage 4. RC incidence was only slightly different in 2003, with 2%, 31%, 22%, 21%, and 15% diagnosed in Stages 0–4, respectively. Overall 5-yr survival rates among CC patients significantly (P<.001) improved from 43% to 47% between 1988–1999 (the last year for which 5-yr survival rates are available; see Table). Overall 5-yr survival among RC patients improved from 41% to 47% (P<.001) between 1988–1999. Nearly all of the gain in CC survival has been among Stage 3 patients, whereas the gain in RC survival has been more substantial and more evenly spread across stages. Conclusions: Rectal cancer is more likely to be diagnosed at Stage 0 or 1 than colon cancer. The changing distribution of cancer stage to include more patients diagnosed at the earliest stages, particularly in colon cancer, indicates possible progress in CRC screening. 5-Year Survival by Diagnosis Year, Site, and Stage Cancer Site Year of Diagnosis Stage 0 Stage 1 Stage 2 Stage 3 Stage 4 All stages Colon 1988 .72 .69 .57 .37 .03 .43 1999 .70 .70 .58 .43 .05 .47 Rectal 1988 .59 .62 .49 .35 .02 .41 1999 .74 .67 .53 .45 .04 .47 Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration GE Healthcare GE Healthcare