The widow of a Wheaton man who died of cancer in 1980 received a $395,000 settlement yesterday just before her malpractice case against a Silver Spring internist was to go to trial in Montgomery County Circuit Court.

The widow of the 57-year-old man, Jacob Cohen, had sued Dr. Allan Cohan, arguing that he had failed to properly diagnose her husband's cancer of the colon in 1976, according to her attorney, Aaron Levine.

Levine said that in 1976 a radiologist X-rayed Cohen's colon, a part of the large intestine, and told the internist a "lesion in the right colon cannot be excluded" and suggested "a repeat examination should be given."

Levine said Dr. Cohan did not order a second X-ray, but instead treated the patient for a thyroid problem. Two years later, according to Levine, cancer of the colon was diagnosed and in May 1980 Cohen died after the cancer had spread.

Laurence Scott, who represented Dr. Cohan, said his client "does not believe he is in any way responsible" for the death, but that his malpractice insurer insisted upon settling.

Scott said the radiologist's report also stated that the X-ray "shows something that is probably feces," and Cohan made a "clinical judgment that what appeared on the X-ray was feces and not a cancerous lesion."