A statistical note on the association of colorectal cancer and lymphoma.

Four patients are presented who were ascertained to have synchronous primary neoplasms-adenocarcinoma of the colon and lymphoma. The age-specific incidence of these lesions is used to compute the expected incidence of this joint occurrence in the aggregate. A hypothesis is proposed to explain the association between adenocarcinoma of the colon and lymphoma. The available data concerning the incidence of multiple primary malignancy of different organs is briefly discussed. It is suggested that data pertaining to multiple primary malignancies of different organs is confused as a result of pooling heterogeneous groups.