Consolidation radiotherapy following carboplatin-based chemotherapy in radically operated advanced ovarian cancer. A pilot study

Continued chemotherapy after complete response to primary therapy among women with advanced ovarian cancer: a meta-analysis

BACKGROUND

Ovarian cancer (OC) is associated with a >75% risk of recurrence after completion of primary therapy. Several clinical trials have explored the role of continued therapy after complete response to primary adjuvant therapy to reduce the risk of recurrence; however, these trials have largely been underpowered, leading to inconclusive results.

METHODS

A systematic search strategy was initiated to identify all clinical trials involving consolidation or maintenance therapy regimens for OC in first complete remission. A meta-analysis was conducted to evaluate toxicity and progression-free (PFS) and overall survival (OS).

RESULTS

There were 37 publications meeting all eligibility criteria, representing 20 consolidation and 9 maintenance therapy trials. Consolidation and maintenance therapies were associated with improved PFS (hazard ratio [HR], 0.79 [P = .003] and HR, 0.82 [P = .02], respectively) and OS (HR, 0.68 [P = .0008] and HR, 0.68 [P = .007], respectively). This relationship remained statistically significant when the analysis was limited to randomized trials and across other sensitivity analyses.

CONCLUSIONS

Although individual studies have not yet convincingly shown a survival advantage with maintenance chemotherapy in OC, this meta-analysis demonstrates that continued chemotherapy after completion of primary therapy for OC improves PFS and OS. Benefits are greatest in patients with advanced stage OC who reach complete clinical or pathologic response after primary therapy.

Consolidation and maintenance treatments for patients with advanced epithelial ovarian cancer in complete response after first-line chemotherapy: A review of the literature

Most patients with advanced epithelial ovarian cancer experience objective responses to paclitaxel/platinum-based chemotherapy, but responses are generally short-lived and the clinical outcome is still unsatisfactory. Therefore, the strategy to consolidate and to prolong the duration of response is very attractive. Different consolidation or maintenance treatments have been attempted, such as whole abdomen radiotherapy, intraperitoneal chromic phosphate, radioimmunotherapy, intraperitoneal chemotherapy, high-dose chemotherapy with haematopoietic support, prolonged administration of the first-line regimen, second-line single-agent chemotherapy, and biological agents. Clinical studies have given conflicting, inconclusive, and generally disappointing results. A recent US randomised trial appeared to show that the prolonged administration of single-agent paclitaxel (175 mg/m2 every 3 weeks) significantly improved the progression-free survival of complete responders to paclitaxel/platinum-based chemotherapy. Alternative less toxic, and probably more effective schedules of administration of chemotherapy (i.e. weekly paclitaxel) might assure a better balance between quality of life and anti-tumor activity in patients previously exposed to chemotherapy.

Consolidation treatment of advanced ovarian carcinoma with radiotherapy after induction chemotherapy

In a prospective randomized trial, consolidation treatment with radiotherapy or chemotherapy was compared with no treatment in a series of 172 patients with epithelial ovarian carcinoma, FIGO stage III, with complete surgical remission after primary cytoreductive surgery and induction chemotherapy. In the subgroup with complete pathological remission, progression-free survival (PFS) was significantly (P = 0.032) better in the radiotherapy group (56%) than in the chemotherapy group (36%) and the untreated control group (35%). The number of recurrences was lowest in the radiotherapy group. The overall relapse rate was reduced by 33% and the pelvic recurrences by 43% by consolidation radiotherapy. On the other hand, treatment-related side effects were more frequent in the radiotherapy group.

Consolidation treatment of advanced (FIGO stage III) ovarian carcinoma in complete surgical remission after induction chemotherapy: a randomized, controlled, clinical trial comparing whole abdominal radiotherapy, chemotherapy, and no further treatment

In a prospective randomized trial, consolidation treatment with radiotherapy or chemotherapy was compared with no treatment in a series of 172 patients with epithelial ovarian carcinoma, FIGO stage III, with complete surgical remission after primary cytoreductive surgery and induction chemotherapy. In the subgroup with complete surgical and pathologic remission, progression-free survival was significantly (P = 0.032) better in the radiotherapy group (56% at 5 years) than in the chemotherapy group (36% at 5 years) and the untreated control group (35% at 5 years). Overall survival was also most favorable in the radiotherapy group (69% at 5 years). The number of recurrences was lowest in the radiotherapy group. In the subgroup with microscopic residual carcinoma there were no significant differences in survival between the radiotherapy and the chemotherapy-treated patients. Early and late radiation reactions were recorded. Treatment-related side effects were seen most frequently in the radiotherapy group. Late intestinal radiation reactions of a severe type were recorded in 10%.

Consolidation radiotherapy after carboplatin-based chemotherapy in radically operated advanced ovarian cancer

OBJECTIVE

The aim of the study was to evaluate the effect of additional radiotherapy after chemotherapy on the relapse-free and overall survival rates of patients with advanced ovarian cancer.

METHODS

Between 1985 and 1992 64 patients with radically operated ovarian cancers (4 stage IC, 2 stage II, 54 stage III, and 4 stage IV) were enrolled in a randomized study. Radical surgery comprised total abdominal hysterectomy and bilateral salpingo-oophorectomy, omentectomy, and pelvic and paraaortic lymphadenectomy. All patients received adjuvant chemotherapy with carboplatin IV 400 mg/m2, epirubicin IV 70 mg/m2 on day 1 and prednimustine orally 100 mg/m2 on days 3 to 7 at 1-month intervals. Thirty-two patients without residual disease were randomized to whole abdominal radiation (30 Gy, administered over 4 weeks). An additional 21.6 Gy were delivered to the pelvis and 12 Gy to the paraaortic region up to the diaphragm for total doses of 51.6 and 42 Gy, respectively. Cancer-related survival was calculated with the Kaplan-Meier and Cox proportional hazards methods.

RESULTS

The relapse-free and overall survival rates of patients who received adjuvant chemoradiotherapy were significantly higher than those of patients who received adjuvant chemotherapy only (68% vs 56% at 2 years and 49% vs 26% at 5 years, P = 0.013, and 87% vs 61% at 2 years and 59% vs 33% at 5 years, P = 0.029). The differences were most pronounced in patients with stage III disease (77% vs 54% at 2 years and 45% vs 19% at 5 years, P = 0. 0061, and 88% vs 58% at 2 years and 59% vs 26% at 5 years, P = 0. 012). Toxicities were acceptable.

CONCLUSION

Sequential combination of platinum-based chemotherapy with open-field abdominal radiotherapy is a promising adjuvant regimen for patients with advanced ovarian cancer.