Clinicopathological features of signet-ring cell carcinoma of the colon and rectum: a case-matched study.

BACKGROUND/AIMS: Primary colorectal signet-ring cell carcinoma (SRC) is a rare type of mucin-containing adenocarcinoma and little information exists about its clinicopathological features. METHODS: The clinicopathological features of 27 patients with primary colorectal SRC were compared with non-signet-ring cell mucinous carcinoma (MC) and non-mucinous adenocarcinoma (NMC). To analyze survival and recurrence, we used matched control groups. RESULTS: The mean age of patients in SRC was significantly younger than that of NMC (p = 0.003). The ratio of metastatic lymph nodes to harvested lymph nodes was also significantly higher in SRC (48.5 +/- 30.6) than in either MC (29.8 +/- 26.3; p = 0.009) or NMC (22.0 +/- 21.6; p = 0.003). In stage II and III, SRC was found to be associated with a worse cancer-specific survival and a higher systemic recurrence rates than either NMC or MC. CONCLUSIONS: Primary colorectal SRC has distinctive clinicopathological features and is associated with a poorer prognosis than the other histological subtypes.

Long-term oncologic results of patients with distal rectal cancer treated by local excision with or without adjuvant treatment.

AIM: The aim of this study is to review long-term oncologic results of local excision (LE) and to investigate the validity and feasibility of LE as a treatment option for distal rectal cancer. MATERIALS AND METHODS: Seventy-six patients who underwent LE for distal rectal adenocarcinoma with curative intent from 1991 to 2000 at Severance Hospital Yonsei University Medical Center, Seoul, Korea were enrolled in this study. RESULTS: Preoperative transrectal ultrasonography revealed 3 cases of uT0, 55 cases of uT1 and 18 cases of uT2. Postoperative pathologic examination revealed 10 cases of pT0 (where no residual cancer cells remained), 11 cases of pTis, 37 cases of pT1, 16 cases of pT2, and 2 cases of pT3. Eleven out of 37 patients with pT1 tumors received adjuvant radiation therapy. Among 16 patients with pT2 tumor, 7 undertook salvage operation and 8 received adjuvant therapy. The median follow-up period was 84.9 months. Local recurrence was observed in six patients. The 5-year local recurrence-free survival rate (LFS) was 89.4% in the pT1 group and 75.0% in the pT2 group (p = 0.012). Among the patients with pT1 cancer, those who received adjuvant radiation therapy demonstrated a 5-year LFS of 100%, compared to those who did not, 76.0% (p = 0.038). CONCLUSION: Our results imply a potential role of LE and adjuvant radiation as an option for the treatment of distal rectal cancer, and that even for pT1 carcinoma, LE alone might not be a valid modality.