Variables related to risk of recurrence in rectal cancer without lymph node metastasis

There has been recent interest in the use of local excision for rectal cancer under consideration of patient's quality of life. However, local excision of the primary tumor does not remove the areas of lymphatic spread. Therefore, the decision to use this procedure must be considered carefully.

The authors retrospectively analyzed 142 patients who underwent radical resection of rectal cancer without lymph node metastasis in order to define the risk factors for recurrence. The macroscopic and microscopic pathological characteristics, immunohistochemical staining for p53, and DNA ploidy pattern of the primary tumor were examined as potential predictors of recurrence.

The rates for 5-year disease-free survival, local control, freedom from distant metastasis, and overall survival in these 142 patients were 87%, 93%, 93%, and 91%, respectively. Factors related to recurrence and prognosis included the depth of tumor invasion, vascular/lymphatic involvement, tumor differentiation, and tumor size. However, p53 staining and DNA ploidy pattern were not useful indicators.

Our findings suggest that adjunctive radiotherapy and chemotherapy should be considered for patients who have rectal cancer without lymph node metastasis in the following situations: tumor invasion of the serosa, vascular/lymphatic involvement, moderately differentiated adenocarcinoma, and lesions > 2 cm in diameter. Local excision should not be used in these situations, even if there are no lymph node metastases.