Detection and localization of ovarian cancer with radiolabeled monoclonal antibodies

Second-look and second surgery: second chance or second best?

About 40 years ago, second-look laparotomy (SLL) was introduced to evaluate, surgically and pathologically, primary treatment in case a clinical complete remission was obtained in ovarian cancer patients. But does SLL increase the disease-free or overall survival? Important technical aspects of the procedure as: how many biopsies should be taken, can laparoscopy be replaced by laparotomy and should complete lymphadnectomy be performed at SLL, are still not clarified. This and maybe even more important issues, are disputed in literature: for instance, should a SLL be done at all, or should a SLL be performed in order to do a secondary cytoreduction in case tumour is found at the operation. If clinical remission is reached in more than 50% of the patients with advanced disease, tumour still can be found at SLL. If no tumour is found at SLL, macroscopically or microscopically, the operation is redundant. Apart from this, the recurrence rate after such a "negative SLL" is about 35%. Whether tumour found at SLL should be removed will depend on the fact if the tumour still is responsive to chemotherapy. To minimise the chance of tumour resistance, secondary surgery should be done as early as possible during treatment. Therefore, an interval debulking will be the intervention of choice. So, as long as there is no evidence that SLL increases the survival in ovarian cancer patients, it should be done in a research setting only. Also, the usefulness of secondary surgery for recurrent disease mainly depends on the chemo-sensitivity of the tumour. After a complete remission, which lasts for more than a year, complete secondary cytoreduction, again followed by chemotherapy, improves survival.

Immunoliposome-mediated targeting of doxorubicin to human ovarian carcinoma in vitro and in vivo

This paper deals with the utility of immunoliposomes for the delivery of doxorubicin (DXR) to human ovarian carcinoma cells in vitro and in vivo. We aimed to investigate whether immunoliposome-mediated targeting of DXR to ovarian cancer cells translates in an enhanced anti-tumour effect compared with that of non-targeted DXR liposomes (lacking the specific antibody). Target cell binding and anti-tumour activity of DXR immunoliposomes were studied in vitro and in vivo (xenograft model of ovarian carcinoma). In vitro we observed that target cell binding and cell growth inhibition of DXR immunoliposomes is superior to that of non-targeted DXR-liposomes. However, in vivo, despite the efficient target cell binding and good anti-tumour response of DXR-immunoliposomes, no difference in anti-tumour effect, compared with non-targeted DXR-liposomes, could be determined. The results indicate that premature DXR leakage from immunoliposomes occurring before the actual target cell binding and subsequent DXR association with the tumour cells, explains why no significant differences in anti-tumour activity between DXR-immunoliposomes and non-targeted DXR-liposomes were observed in vivo.

Monoclonal antibodies in ovarian and prostate cancer

Radioimmunoscintigraphy (RIS)--using radiolabeled monoclonal antibodies (MoAbs) to image disease--is a growing subspecialty of nuclear medicine. RIS of the reproductive tracts of men and women has shown encouraging results in imaging both primary lesions and metastases of these cancers. Ovarian cancer is the most fatal gynecologic cancer in the United States, and prostate cancer is the most prevalent form of cancer in men. Several MoAbs against reproductive tumor antigens were used with limited success in clinical trials before 1989. Most recently, MoAbs CYT-103 (satumomab pendetide) and OV-TL 3 have shown promise as safe, sensitive imaging tools for ovarian cancer. Although to date more agents have been used to image ovarian carcinoma than prostate cancer, research has been restimulated in prostate carcinoma imaging because of development of a promising MoAb conjugate, CYT-356. Radionuclide indium-111 appears to be the most promising radiolabeled to date for ovarian and prostate carcinoma RIS performed in the United States. In future clinical trials, consideration of safety issues and a standardization of methods among institutions using RIS are needed before the use of MoAb technology in cancer imaging will become routine. Comparative studies with more traditional methods like computed tomography are needed, as well as more trials comparing radioimmunoscintigraphic findings with pathological evidence.