When and how should adjuvant radiation be used in early endometrial cancer?

The role of adjuvant radiation therapy (RT) in early endometrial cancer is no longer clearly defined. The increased use of surgical lymph nodes staging and the perceived "lack of survival advantage" with adjuvant pelvic RT leads to a wide array of conclusions on who should be treated and if so how. The purpose of this review is 2-fold: first, to determine the scientific validity of some of the conclusions drawn about the lack of survival impact of adjuvant pelvic RT and, second, to determine which treatment option provides the best therapeutic ratio. Overall survival may not be the ideal endpoint for early-stage endometrial cancer where death more often than not is because of causes other than endometrial cancer. Observation after hysterectomy may have the best morbidity profile, yet it may not be the option with the best therapeutic ratio. Finding a suitable alternative such as intravaginal RT or using intensity-modulated radiation therapy may ultimately prove to be the option with the best therapeutic ratio. The data learned from surgical lymph nodes staging and from the 2 recent randomized trials on the role of pelvic RT in early endometrial cancer need not be ignored nor held as the final answer. Perhaps, rectal cancer should be used as an example of how an incremental use of individual adjuvant therapies, each impacting outcome little at a time, ended up improving overall survival. If we were to use the current prevailing approach in endometrial cancer for rectal cancer, patients would still be treated with surgery alone.