Provided are methods of determining a response to a chemotherapeutic agent in a subject with ovarian cancer, comprising: determining a RNA integrity value of a sample comprising ovarian cancer cell RNA from the subject after the subject has received one or more doses of the chemotherapeutic agent; wherein a low RNA integrity value and/or RNA degradation of the cancer cell RNA is indicative that the cancer is responding to the chemotherapeutic agent and/or a high RNA integrity value and/or stable RNA integrity of the ovarian cancer cell RNA is indicative that the cancer is resistant to the chemotherapeutic agent.