The clinical staging of rectal cancer

Abstract

The ability of rectal digital examination to recognize significant stages of local extent and lymph node involvement in adenocarcinoma of the lower two-thirds of the rectum was investigated. Seventy patients with a palpable rectal cancer were examined by 2 or 3 out of a panel of 10 clinicians including 2 consultants and 8 registrars. A defined protocol was used and the results were recorded on a proforma. Clinical findings were compared with the results of pathological examination of the resected specimen or the final surgical assessment when the growth was not removed. In 38 patients computed tomography of the primary growth was performed and the results were also compared to the pathological findings. Four groups of cases with different degrees of extent of spread were recognized by digital examination in 67–83 per cent by consultants and in 44–78 per cent by registrars. Computed tomography correctly identified growths with extensive local spread in 89 per cent of cases, but was no more reliable than digital examination in the assessment of other degrees of spread or of lymph node involvement. Based on the results, a clinical staging system is proposed, comprising four stages of local extent as follows—stage 1: confined to rectum; stage 2: confined to rectum or slight extrarectal spread; stage 3: moderate or extensive extrarectal spread; stage 4: involvement of other organs or unresectability. Two stages of lymph node involvement are also proposed: namely, node negative and node positive. Each stage corresponds to different survival and local recurrence rates after surgery. Combined with other factors, such as level and size of tumour, histological grade and the general state of the patient, the clinical staging system may facilitate the choice of treatment. It might extend the use of major sphincter-saving procedures, indentify many patients suitable for local treatment and define those with a considerable risk of local recurrence where combined surgery and radiotherapy might be considered.