Cost-effectiveness of second curettage for treatment of low-risk non-metastatic gestational trophoblastic neoplasia

OBJECTIVE

Low-risk non-metastatic gestational trophoblastic neoplasia (GTN) has been treated with single agent chemotherapy, but second curettage is emerging as an alternative strategy with reported cure rates of 40%. We sought to estimate the cost-effectiveness of second curettage as the first line treatment of low-risk GTN.

METHODS

A decision-analytic model was created using TreeAge software to compare costs and outcomes for women with WHO staged low-risk GTN undergoing treatment with 5-day methotrexate (MTX), biweekly pulsed actinomycin-D, or second curettage. Probabilities were derived from the literature. Outcomes of interest included side effects from chemotherapy, need for additional agents, hemorrhage, uterine perforation, and cure rates. Utilities were applied to discounted life expectancy at a rate of 3% to generate quality adjusted life years (QALYs). Sensitivity analyses were then performed in order to assess the robustness of our assumptions.

RESULTS

Of the three treatment arms, MTX was associated with the lowest cost and had similar QALYs to the other studied modalities. Second curettage was associated with 49 additional cures when applied to a theoretic cohort of 1000 women, as well as an additional 83 hemorrhages and 17 uterine perforations. Sensitivity analysis on the cure rate of second curettage revealed that second curettage was not cost-effective over MTX unless its probability of cure was 98%.

CONCLUSION

Our study found 5-day MTX was the cost-effective strategy for treatment of women with low-risk, non-metastatic GTN when compared to second curettage and actinomycin-D. In a carefully selected patient population, second curettage may be an additional treatment strategy.

A cost analysis of first-line chemotherapy for low-risk gestational trophoblastic neoplasia

OBJECTIVE

To determine the optimal approach to first-line treatment for low-risk gestational trophoblastic neoplasia (GTN) using a cost analysis of 3 commonly used regimens.

STUDY DESIGN

A decision tree of the 3 most commonly used first-line low-risk GTN treatment strategies was created, accounting for toxicities, response rates and need for second- or third-line therapy. These strategies included 8-day methotrexate (MTX)/folinic acid, weekly MTX, and pulsed actinomycin-D (act-D). Response rates, average number of cycles needed for remission, and toxicities were determined by review of the literature. Costs of each strategy were examined from a societal perspective, including the direct total treatment costs as well as the indirect lost labor production costs from work absences. Sensitivity analysis on these costs was performed using both deterministic and probabilistic cost-minimization models with the aid of decision tree software (TreeAge Pro 2011, TreeAge Inc., Williamstown, Massachusetts).

RESULTS

We found that 8-day MTX/folinic acid is the least expensive to society, followed by pulsed act-D ($4,867 vs. $6,111 average societal cost per cure, respectively), with act-D becoming more favorable only with act-D per-cycle cost <$231, or response rate to first-line therapy > 99%. Weekly MTX is the most expensive first-line treatment strategy to society ($9,089 average cost per cure), despite being least expensive to administer per cycle, based on lower first-line response rate. Absolute societal cost of each strategy is driven by the probability of needing expensive third-line multiagent chemotherapy, however relative cost differences are robust to sensitivity analysis over the reported range of cycle number and response rate for all therapies.

CONCLUSION

Based on similar efficacy and lower societal cost, we recommend 8-day MTX/folinic acid for first-line treatment of low-risk GTN.