Abstract
A total of 250 patients with rectal adenocarcinoma were operated on at the University of Chicago Medical Center between 1965 and 1981. The operation performed was curative resection in 154 patients, palliative resection in 16 patients, diverting colostomy in 21 patients, exploratory laparotomy in 11 patients, and transanal removal in 48 patients. Of the 154 curative resections, 115 were abdomino-perineal (APR), three were total proctocolectomies, and 36 were low anterior resections (LAR). No anastomotic complications were observed in this latter group. Operative mortality was 3%. Complete follow-up was obtained in 152 patients (98.7%). Five- and 10-year actuarial survival rates were 68.8 and 59.4%, respectively, for patients with Dukes' B1 adenocarcinoma (n = 32), 55.8 and 44.2% for Dukes' B2 tumors (n = 52), and 42.9% and 25.4% for Dukes' C tumors (n = 63). Distant metastases developed in 59 patients (39.6%), and pelvic recurrence developed in another 18 patients (12%); 5-year survival rates were 23.6% and 22.2%, respectively. Multivariate analysis with Cox regression showed that stage (p = 0.0001), race (p = 0.03), tumor morphology (p = 0.02), and vascular and/or lymphatic microinvasion (p = 0.001) were statistically significant in their association with survival. Logistic regression analysis confirmed these results and allowed for the estimation of 5-year survival probabilities in 16 groups of patients defined by various associations of these four factors. These estimates ranged from a high of 92% in Caucasian patients with Stage B, exophytic tumors with no vascular or lymphatic microinvasion, to a low of 14% in black patients with Stage C, nonexophytic tumors and with the presence of vascular and/or lymphatic microinvasion. Univariate analysis showed that histologic type (p = 0.0006), stage (p = 0.05) and vascular and/or lymphatic microinvasion (p less than 0.001) were significantly associated with the incidence of pelvic recurrence. Analysis of the extent of the operation revealed that the incidence of pelvic recurrence was reduced by the performance of a wide pelvic lymphadenectomy (9.4% vs. 16.4%), but the result did not reach statistical significance (p = 0.16). In conclusion, this study confirms the well-established prognostic value of the Dukes' staging classification of rectal carcinoma. Further, the analysis reveals that race, tumor morphology, and the presence or absence of lymphatic and/or vascular microinvasion significantly influence outcome. By associating these four statistically significant and independent variables, the prognosis for any individual patient can be estimated more precisely than by using Dukes' staging alone.(ABSTRACT TRUNCATED AT 400 WORDS)