Radium and X-ray Therapy as Palliative Measures in the Treatment of Rectal Cancer

Abstract

EXCLUSIVE of the stomach and oral cavity, approximately 60 per cent of the remaining intestinal cancers are indigenous to the rectum. Rectal cancers are notoriously difficult to cure because 40 to 50 per cent are inoperable when first seen by the surgeon; the rectum is in daily use; the tumor mass is not easily accessible; the degree of dissemination cannot be estimated by physical examination; the complete removal of all cancer-bearing tissue is a difficult operative feat accompanied by a high immediate mortality. The Pathology of Rectal Carcinomas Epithelioma or squamous-cell carcinoma of the anus is uncommon, aggregating only 3 to 4 per cent of all rectal cancers. Its site of predilection is at the mucocutaneous junction in the mid-line, anteriorly. It forms a nodular, warty, flattened growth which tends to ulcerate and involve the rectum proper. Its radiosensitivity corresponds with that of the lip and the buccal mucosa; the most satisfactory plan of treatment is irradiation by the interstitial deposition of small metal-filtered radon implants, known as gold or platinum seeds. The remaining cancers of this region are adenocarcinomas, which are also the most frequent tumors. The symptomatology, growth tendencies, and pathology of these differ according to their location in the rectal canal. At the rectosigmoidal junction the tumor early encircles the bowel to form an annular stricture. The majority of carcinomas of the rectal ampulla begin on the posterior wall. The four common types of adenocarcinomas of this region are: (1) The papillary carcinoma. (2) The malignant adenoma, or adenoma destruens. (3) The colloid, or gelatinous carcinoma. (4) The scirrhus or fibrocarcinoma. The papilliferous, or papillomatous, carcinoma resembles the benign papilloma somewhat, except for the invasive nature of its base. This tumor may be frankly malignant from its onset, or it may be a malignant degeneracy of the benign papilloma. Its growth energy is expended largely by evertent or surface proliferation, producing a bulky exuberant tumor, before the bowel wall is infiltrated. This cancer is readily amenable to surgical extirpation; when radium therapy is to be employed, the papilliferous fronds are removed by surgical endothermy and gold or platinum filtered radon seeds are implanted into the base of the cancer. The scirrhus or fibrocarcinoma is a peculiar type of rectal carcinoma, exhibiting desmoplastic tendencies, in which the atypical cancer cells are growing diffusely and are nestled away among wide strands of new connective tissue. This cancer is markedly radioresistant. The colloid or gelatinous carcinoma is a degenerative type of adenocarcinoma. It usually forms a bulky, massive growth in which gelatinous or mucoid material replaces the tumor tissue. It likewise does not respond well to radiation therapy. Adenoma destruens is the most common type of cancer of the rectum.