The lifespan of ovarian cancer patients depends on several factors including the specific stage of the cancer, the patient's sensitivity and response to treatment, and the overall health of the patient, leading to significant individual variability. The cancer is typically classified into stages from one to four, with stage one being the earliest and stage four being the most advanced. Generally, patients diagnosed at an earlier stage tend to have a better prognosis and a greater chance of survival compared to those with advanced ovarian cancer. Additionally, patients in advanced stages who respond well to treatments like chemotherapy typically have a better prognosis and longer survival times compared to those who are less responsive to such treatments. Hence, it is impossible to generalize as the individual differences are substantial.