Radioactive Phosphorus (P³²) in the Diagnosis of Gastrointestinal Cancer

Abstract

Clinical use of the radioactive phosphorus (P³²) test naturally expanded first in the more accessible regions of the body. Areas such as the eye, skin and breast could be carefully evaluated for relatively long periods and, if necessary, repeatedly with little discomfort to the patient. The difficulty of instrumentation in the gastrointestinal tract presented a natural barrier to clinical evaluation. During the period of early delay, a basic study (Schulman et al., 1949) on phosphorus turnover in human gastric carcinoma, shed some light on the possible usefulness of the test in the stomach. Following subtotal gastrectomy in three patients with nonmalignant disease and six with various gross types of cancer, who had been given 1 µc. of P³² per pound of body weight 36 hours prior to surgery, mucosa was stripped from the stomach wall in all cases, and samples taken of tumor mass. Analysis showed that the phosphorus content of mucosa from stomach with either benign or malignant disease, was essentially the same. The phosphorus content of gastric mucosa, whether associated with benign or malignant disease, and cancerous tissue, was also the same, but the rate of phosphorus turnover was 47 per cent higher in gastric carcinoma than in other gastric tissue. There was a 124 per cent increase in the turnover of protein phosphorus and a 45 per cent increase in the turnover of lipid phosphorus, but the acid-soluble phosphorus turnover remained unchanged. The increased activity of tumor phosphorus in the stomach demonstrated the possible usefulness of the P⁸² test in differential diagnosis of gastric lesions.