Patients that are placed in group an are resistant to primary therapy and have tumor growth during treatment. Treatment suggested is non-cross resistant chemotherapies or biological therapies.
Patients that are placed in-group B are those who have responded well to the initial chemotherapy, but developed recurrent cancer within months of the primary treatment.
Patients that are placed in-group C are those who showed good response to the initial chemotherapy but then developed recurrent cancer for more than 6 months after the end of their initial treatment.
The size of the recurring tumor (largest of the tumors if multiple), and the number of disease sites and histology will determine the response to salvage chemotherapy.
The patient’s degree of “platinum drug resistance” dictates how the patient will respond to salvage chemotherapy.
Platinum resistance is defined as disease progression while on the first-line platinum-based regimen, tumor progression within 6 months of completion of the therapy, persistent clinically measurable disease, as stable disease at the completion of the first-line therapy, and while receiving first-line non-protocol therapy, with rising CA 125 levels documented and two examinations with a result of 100 or greater than 100.
The period of time between relapse and the end of initial chemotherapy is the most commonly used indicator of resistance. The longer the length of time between these two points usually means the better chances of responding to salvage chemotherapy.
Typically 25% respond when the time period between is 6 to 12 months and 33% for 12 to 24 months and 60% for greater than 24 months.
Sensitive Ovarian Cancer
Sensitive Cancer can be treated in patients with recurrent chemotherapy-sensitive disease are treated with initial chemotherapy (carboplatin/paclitaxel) with toxicity considered.
If only carboplatin or cisplatin was used for the initial therapy than taxol may be used for salvage chemotherapy. If the cancer is low-volume, intraperitoneal chemotherapy or radiotherapy can be used. Trial of high dose chemotherapy with autologous bone marrow support may also be considered.
Long-term outcomes are at risk when drug-resistant tumors are discovered during therapy for ovarian cancer. Research is ongoing and clinical trials of non-cross-resistant antineoplastic agents. Another investigation is ongoing regarding intraperitoneal therapy with many innovative treatment strategies being targeted, including anticancer vaccines, gene therapy, antiangiogenic therapy. All women who have been diagnosed with advanced ovarian cancer should be considered for clinical trials.
Patients who have platinum-resistant cancer and who have not received taxol during the initial chemotherapy should be considered for Taxol therapy.
Patients with resistance to primary chemotherapy have received high response rates (70% to 82%) when receiving high-dose chemotherapy accompanied with Autologous Bone Marrow Transplantation (ABMT) and also Peripheral Blood Stem Cell transplantation (PBSCT). This regimen is usually limited to clinical trials and tested for use in first-line therapy.