Citations

Purpose We update Radiation Therapy Oncology Group trial 8911 (USA Intergroup 113), a comparison of chemotherapy plus surgery versus surgery alone for patients with localized esophageal cancer. The relationship between resection type and between tumor response and outcome were also analyzed. Patients and Methods The chemotherapy group received preoperative cisplatin plus fluorouracil. Outcome based on the type of resection (R0, R1, R2, or no resection) was evaluated. The main end point was overall survival. Disease-free survival, relapse pattern, the influence of postoperative treatment, and the relationship between response to preoperative chemotherapy and outcome were also evaluated. Results Two hundred sixteen patients received preoperative chemotherapy, 227 underwent immediate surgery. Fifty-nine percent of surgery only and 63% of chemotherapy plus surgery patients underwent R0 resections (P = .5137). Patients undergoing less than an R0 resection had an ominous prognosis; 32% of patients with R0 resections were alive and free of disease at 5 years, only 5% of patients undergoing an R1 resection survived for longer than 5 years. The median survival rates for patients with R1, R2, or no resections were not significantly different. While, as initially reported, there was no difference in overall survival for patients receiving perioperative chemotherapy compared with the surgery only group, patients with objective tumor regression after preoperative chemotherapy had improved survival. Conclusion For patients with localized esophageal cancer, whether or not preoperative chemotherapy is administered, only an R0 resection results in substantial long-term survival. Even microscopically positive margins are an ominous prognostic factor. After a R1 resection, postoperative chemoradiotherapy therapy offers the possibility of long-term disease-free survival to a small percentage of patients.

Recently, the size of the active stem cell pool has been predicted to scale allometrically with the adult mass of mammalian species with a 3/4 power exponent, similar to what has been found to occur for the resting metabolic rate across species. Here we investigate the allometric scaling of human haemopoietic stem cells (HSCs) during ontogenic growth and predict a linear scaling with body mass. We also investigate the allometric scaling of resting metabolic rate during growth in humans and find a linear scaling with mass similar to that of the haemopoietic stem cell pool. Our findings suggest a common underlying organizational principle determining the linear scaling of both the stem cell pool and resting metabolic rate with mass during ontogenic growth within the human species, combined with a 3/4 scaling with adult mass across mammalian species. It is possible that such common principles remain valid for haemopoiesis in other mammalian species.