Research at Cornell: Why is testicular cancer is so easy to treat with chemotherapy?

Advances in chemotherapy have become an important method of cancer treatment, but many cancers still have a poor prognosis and do not respond well to chemotherapy. One type of cancer which has shown astonishing levels of response to chemotherapy is testicular cancer: in 1970, only 5% of patients with highly advanced testicular germ cell tumors survived to the 5 year mark; this number increased to 74% by the early 2000’s, a survival rate which remains considerably higher than other advanced solid cancers. This improvement has been attributed to the sensitivity of testicular germ cell cancer cells to chemotherapy. The million-dollar question remains: why this treatment is so effective in testicular cancer, and not in other types of cancer?

Tim Pierpont, a graduate student in Robert Weiss’ lab at Cornell, believes that the answer may lie in the unique properties inherited from the cells that gave rise to the tumor. Most testicular cancers arise from the germ cells (the precursors to sperm, or an egg in females), and the few that arise from other parts of the organ (5%) have much poorer outcomes. The unique properties of the germ cells may thus explain why these tumor cells are much more sensitive to the effects of chemotherapy.

Tim is studying the mechanism of DNA damage response in these cancerous germ cells. Because germ cells are the cells that eventually give rise to an embryo, any DNA damage, or mistakes made during DNA damage repair, could be passed on to the next generation with devastating results. Germ cells are thus much more likely than other cells to die if DNA damage is detected. Chemotherapy drugs that work by causing DNA damage are thus extremely effective in eradicating testicular germ cell cancer cells.

Tim’s results will help explain why testicular cancer is so easy to attack with chemotherapy, and hopefully offer clues on how to make other tumors similarly sensitive to chemotherapy.

Many thanks to Tim Pierpont who sat down with me to talk about his research and elucidated many aspects of DNA damage!