Prognostic value of lateral lymph node metastasis for advanced low rectal cancer

AIM: To evaluate the risk factors for lateral lymph node metastasis in patients with advanced low rectal cancer, in order to make the effective selection of patients who could benef it from lateral lymph node dissection, as well as the relationship of lateral lymph node metastasis with local recurrence and survival of patients with advanced low rectal cancer. METHODS: A total of 96 consecutive patients who underwent curative surgery with lateral pelvic lymphadenectomy for advanced lower rectal cancer were retrospectively analyzed. The relation of lateral lymph node metastasis with clinicopathologic characteristics, local recurrence and survival of patients was identif ied. RESULTS: Lateral lymph node metastasis was observed in 14.6% (14/96) of patients with advanced low rectal cancer. Lateral lymph node metastasis was detected in 10 (25.0%) of 40 patients with tumor diameter ≥ 5 cm and in 4 (7.1%) of 56 patients with tumor diameter < 5 cm. The difference between the two groups was statistically signifi cant (χ2 = 5.973, P = 0.015). Lateral lymph node metastasis was more frequent in patients with 4/4 diameter of tumor infiltration (7 of 10 cases, 70.0%), compared with patients with 3/4, 2/4 and 1/4 diameter of tumor inf iltration (3 of 25 cases, 12.0%; 3 of 45 cases, 6.7%; 1 of 16 cases, 6.3%) (χ2 = 27.944, P = 0.0001). The lateral lymph node metastasis rate was 30.0% (9 of 30 cases), 9.1% (4 of 44 cases) and 4.5% (1 of 22cases) for poorly, moderately and well-differentiated carcinoma, respectively. The difference between the three groups was statistically significant (χ2 = 8.569, P = 0.014). Local recurrence was 18.8% (18 of 96 cases), 64.3% (9 of 14 cases), and 11.0% (9 of 82 cases) in patients with advanced low rectal cancer, in those with and without lateral lymph node metastasis, respectively. The difference between the two groups was statistically signif icant (χ2 = 22.308, P = 0.0001). Kaplan-Meier survival analysis showed significant improvements in median survival (80.9 ± 2.1 m, 95% CI: 76.7-85.1 m vs 38 ± 6.7 m, 95% CI: 24.8-51.2 m) of patients without lateral lymph node metastasis compared with those with lateral lymph node metastasis (log-rank, P = 0.0001). CONCLUSION: Tumor diameter, infiltration and differentiation are signif icant risk factors for lateral lymph node metastasis. Lateral pelvic lymphadenectomy should be performed following surgery for patients with tumor diameter ≥ 5 cm. Lateral lymph node metastasis is an important predictor for local recurrence and survival in patients with advanced low rectal cancer.

Study of circumferential resection margin in patients with middle and lower rectal carcinoma

AIM: To clarify the relationship between circumferential resection margin status and local and distant recurrence as well as survival of patients with middle and lower rectal carcinoma. The relationship between circumferential resection margin status and clinicopathologic characteristics of middle and lower rectal carcinoma was also evaluated. METHODS: Cancer specimens from 56 patients with middle and lower rectal carcinoma who received total mesorectal excision at the Department of General Surgery of Guangdong Provincial People's Hospital were studied. A large slice technique was used to detect mesorectal metastasis and evaluate circumferential resection margin status. RESULTS: Local recurrence occurred in 12.5% (7 of 56 cases) of patients with middle and lower rectal carcinoma. Distant recurrence occurred in 25% (14 of 56 cases) of patients with middle and lower rectal carcinoma. Twelve patients (21.4%) had positive circumferential resection margin. Local recurrence rate of patients with positive circumferential resection margin was 33.3% (4/12), whereas it was 6.8% (3/44) in those with negative circumferential resection margin (P = 0.014). Distant recurrence was observed in 50% (6/12) of patients with positive circumferential resection margin; conversely, it was 18.2% (8/44) in those with negative circumferential resection margin (P = 0.024). Kaplan-Meier survival analysis showed significant improvements in median survival (32.2 ± 4.1 mo, 95% CI: 24.1-40.4mo vs 23.0 ± 3.5 mo, 95% CI: 16.2-29.8 mo) for circumferential resection margin-negative patients over circumferential resection margin-positive patients (log-rank, P < 0.05). 37% T3 tumors examined were positive for circumferential resection margin, while only 0% T1 tumors and 8.7% T2 tumors were examined as circumferential resection margin. The difference between these three groups was statistically significant (P = 0.021). In 18 cancer specimens with tumor diameter ≥ 5 cm 7 (38.9%) were detected as positive circumferential resection margin, while in 38 cancer specimens with a tumor diameter of < 5 cm only 5 (13.2%) were positive for circumferential resection margin (P = 0.028). CONCLUSION: Our findings indicate that circumferential resection margin involvement is significantly associated with depth of tumor invasion and tumor diameter. The circumferential resection margin status is an important predictor of local and distant recurrence as well as survival of patients with middle and lower rectal carcinoma.

Risk factors for local recurrence of middle and lower rectal carcinoma after curative resection

AIM: To explore the risk factors for local recurrence of middle and lower rectal carcinoma after curative resection. METHODS: Specimens of middle and lower rectal carcinoma from 56 patients who received curative resection at the Department of General Surgery of Guangdong Provincial People's Hospital were studied. A large slice technique was used to detect mesorectal metastasis and evaluate circumferential resection margin status. The relations between clinicopathologic characteristics, mesorectal metastasis and circumferential resection margin status were identified in patients with local recurrence of middle and lower rectal carcinoma. RESULTS: Local recurrence of middle and lower rectal carcinoma after curative resection occurred in 7 of the 56 patients (12.5%), and was significantly associated with family history (c2 = 3.929, P = 0.047), high CEA level (c2 = 4.964, P = 0.026), cancerous perforation (c2 = 8.503, P = 0.004), tumor differentiation (c2 = 9.315, P = 0.009) and vessel cancerous emboli (c2 = 11.879, P = 0.001). In contrast, no significant correlation was found between local recurrence of rectal carcinoma and other variables such as age (c2 = 0.506, P = 0.477), gender (c2 = 0.102, c2 = 0.749), tumor diameter (c2 = 0.421, P = 0.516),tumor infiltration (c2 = 5.052, P = 0.168), depth of tumor invasion (c2 = 4.588, P = 0.101), lymph node metastases (c2 = 3.688, P = 0.055) and TNM staging system (c2 = 3.765, P = 0.152). The local recurrence rate of middle and lower rectal carcinoma was 33.3% (4/12) in patients with positive circumferential resection margin and 6.8% (3/44) in those with negative circumferential resection margin. There was a significant difference between the two groups (c2 = 6.061, P = 0.014). Local recurrence of rectal carcinoma occurred in 6 of 36 patients (16.7%) with mesorectal metastasis, and in 1 of 20 patients (5.0%) without mesorectal metastasis. However, there was no significant difference between the two groups (c2 = 1.600, P = 0.206). CONCLUSION: Family history, high CEA level, cancerous perforation, tumor differentiation, vessel cancerous emboli and circumferential resection margin status are the significant risk factors for local recurrence of middle and lower rectal carcinoma after curative resection. Local recurrence may be more frequent in patients with mesorectal metastasis than in patients without mesorectal metastasis.