Dose-intensive approaches to ovarian cancer

Clinical significance of side population in ovarian cancer cells

Recently, accumulating evidence has suggested that tumors, including ovarian cancer, are composed of a heterogeneous cell population with a small subset of cancer stem cells (CSCs) that sustain tumor formation and growth. The emergence of drug resistance is one of the most difficult problems in the treatment of ovarian cancer, which has been explained recently by the potential of CSCs to have superior resistance against anti-cancer drugs than conventional cancer cells. In this study, we expanded this line of study to examine whether this phenomenon is also observed in clinical specimens of ovarian cancer cells. In total we could analyze 28 samples out of 60 obtained from ovarian cancer patients. The clinical samples were subjected to testing of the expression of side population (SP) as a CSC marker, and according to the presence of SP (SP+) or absence of SP (SP−), clinicopathological significances were analyzed. Although there was no statistical significance, there were more SP+s in recurrent cases as well as in ascitic and peritoneal dissemination than in primary tumor of the ovary. There was no correlation between SP status and FIGO staging. In 19 cases of those who could be followed more than 6 months from initial therapy, there were 8 cases of recurrence or death from disease, and all of these were SP+. On the other hand, in 11 cases of disease-free survivors, 6 were SP+. There was a significant difference in prognosis between SP+ and SP− (p = 0.017). Although this study was limited, it revealed that SP could be contained more in recurrent or metastatic tumors than in primary tumors, and also that the presence of SP could be a risk factor of recurrence in ovarian cancer. Therefore, a novel therapeutic strategy targeting SP could improve the prognosis of ovarian cancer.

Chemotherapy intensity and toxicity among black and white women with advanced and recurrent endometrial cancer: a Gynecologic Oncology Group Study

BACKGROUND

The purpose of this study was to confirm whether black and white women with endometrial cancer are equally tolerant of chemotherapy and identify factors that impact survival.

METHODS

A retrospective review of 169 black women and 982 white women with the International Federation of Gynecologists and Obstetricians stage III, stage IV, or recurrent endometrial carcinoma was performed. All patients received doxorubicin combined with cisplatin. Chemotherapy parameters that were reviewed included relative dose, relative time, and relative dose intensity. Treatment cycles > or =7 were defined as treatment completion.

RESULTS

Although black patients were more likely to experience grades 3-4 anemia (20% vs 14%) and genitourinary (5% vs 1%) toxicity, and less likely to experience severe gastrointestinal toxicity (10% vs 17%), the overall incidence of grades 3-4 treatment-related chemotoxicity was the same between the 2 groups (82% vs 82%). There were no differences in the number of cycles received, relative dose (0.57 vs 0.58), relative time (0.77 vs 0.78), or relative dose intensity (0.76 vs 0.76) for black and white patients.

CONCLUSIONS

Black patients with advanced stage or recurrent endometrial cancer, treated on 4 Gynecologic Oncology Group (GOG) protocols, had similar dose intensity and severe chemotherapy-related toxicity compared with white patients, suggesting that previously described racial disparities in survival among patients in GOG trials may have an novel etiology.