After a summer of lawsuits and resignations following the overdose deaths of two patients, the president of the Harvard-affiliated Dana-Farber Cancer Institute has announced his intention to step down.

Dr. Christopher T. Walsh will return to his position as a professor in the Department of Biological Chemistry and Molecular Pharmacology at Harvard Medical School in mid-October.

"I have reached clarity in the decision to return full time to my scholarly activities in research and teaching," Walsh wrote earlier this week in a letter to the Dana-Farber Institute's board of directors.

Boston Globe columnist Betsy Lehman, 39, died at Dana-Farber last year, from an overdose of drugs shielding her from the side effects of chemotherapy.

In a settlement this summer, Dana-Farber agreed to pay an undisclosed amount to Lehman's husband, a Dana-Farber researcher, who will use the money to start a center for breast cancer research.

Subsequent investigations revealed that Lehman's death was just one of dozens of mistakes involving the hospital's patients.

Dr. David M. Livingston '61, former physician-in-chief, and several other top administrators stepped down this spring. Livingston is still director of the institute.

In his letter of resignation, Walsh downplayed the overdoses and investigations.

"This past year has been an especially turbulent one for all of us who work for and with the Institute," he wrote.

"While the overdose tragedies appropriately shook the institution from top to bottom, we have learned much from our self-examination and external scrutiny, and have strengthened Dana-Farber in its patient care mission," Walsh continued.

"I felt it was my responsibility to remain at Dana-Farber until we reached closure on these matters," Walsh wrote. "That time is now past."

Physicians at Dana-Farber referred inquiries about Walsh's resignation and the situation at the hospital to the institute's public affairs office. It released a brief statement saying, "Prof. Walsh's letter of resignation speaks for itself."

Attempts to reach Walsh, Dana-Farber Chair Gary Countryman and several other top administrators were unsuccessful yesterday.