Scott I. Bearman

Bio: Scott I. Bearman is an academic researcher from University of Colorado Denver. The author has contributed to research in topics: Transplantation & Breast cancer. The author has an hindex of 39, co-authored 83 publications receiving 8756 citations. Previous affiliations of Scott I. Bearman include Fred Hutchinson Cancer Research Center & Anschutz Medical Campus.

Nephrectomy followed by interferon alfa-2b compared with interferon alfa-2b alone for metastatic renal-cell cancer.

Abstract: Background The value of nephrectomy in metastatic renal-cell cancer has long been debated. Several nonrandomized studies suggest a higher rate of response to systemic therapy and longer survival in patients who have undergone nephrectomy. Methods We randomly assigned patients with metastatic renal-cell cancer who were acceptable candidates for nephrectomy to undergo radical nephrectomy followed by therapy with interferon alfa-2b or to receive interferon alfa-2b therapy alone. The primary end point was survival, and the secondary end point was a response of the tumor to treatment. Results The median survival of 120 eligible patients assigned to surgery followed by interferon was 11.1 months, and among the 121 eligible patients assigned to interferon alone it was 8.1 months (P=0.05). The difference in median survival between the two groups was independent of performance status, metastatic site, and the presence or absence of a measurable metastatic lesion. Conclusions Nephrectomy followed by interferon ther...

Regimen-related toxicity in patients undergoing bone marrow transplantation.

Abstract: Bone marrow transplantation is associated with significant morbidity and mortality, some of which is due to high-dose chemoradiotherapy. In order to quantitate toxicity that was felt to be due to the preparative regimen (termed regimen-related toxicity [RRT]), a system was developed in which toxicities were graded from 0 (none) to 4 (fatal). One hundred ninety-five patients who underwent marrow transplantation for leukemia were studied retrospectively to determine whether toxicities that were clinically felt to be due to the preparative regimen were influenced by other factors such as disease status, graft-versus-host disease (GVHD) prophylaxis, and allogenicity. All patients developed grade I toxicity in at least one organ, and 30 developed grades III-IV (life-threatening or fatal) RRT. RRT was more common in relapsed patients v remission patients (P = .04), in those receiving 15.75 Gy total body irradiation (TBI) v 12.0 Gy TBI (P = .028), and in those receiving allogeneic marrow v autologous marrow (P = .0029). Autologous marrow recipients did not develop grades III-IV toxicity in this study. A multivariate analysis controlling for autologous marrow grafting showed that the dose of TBI was the only statistically significant predictor of grades III-IV RRT. Those patients who developed grade III RRT were unlikely to survive 100 days from transplant, though not all deaths could be attributed to RRT. Patients who developed grade II toxicity in three or more organs were more likely to die within 100 days than those developing grade II toxicity in two or less organs (P = .0027). This system was generally able to distinguish RRT from other toxicities observed in marrow recipients.

Intratumor heterogeneity and branched evolution revealed by multiregion sequencing.

Abstract: Background Intratumor heterogeneity may foster tumor evolution and adaptation and hinder personalized-medicine strategies that depend on results from single tumor-biopsy samples. Methods To examine intratumor heterogeneity, we performed exome sequencing, chromosome aberration analysis, and ploidy profiling on multiple spatially separated samples obtained from primary renal carcinomas and associated metastatic sites. We characterized the consequences of intratumor heterogeneity using immunohistochemical analysis, mutation functional analysis, and profiling of messenger RNA expression. Results Phylogenetic reconstruction revealed branched evolutionary tumor growth, with 63 to 69% of all somatic mutations not detectable across every tumor region. Intratumor heterogeneity was observed for a mutation within an autoinhibitory domain of the mammalian target of rapamycin (mTOR) kinase, correlating with S6 and 4EBP phosphorylation in vivo and constitutive activation of mTOR kinase activity in vitro. Mutational intratumor heterogeneity was seen for multiple tumor-suppressor genes converging on loss of function; SETD2, PTEN, and KDM5C underwent multiple distinct and spatially separated inactivating mutations within a single tumor, suggesting convergent phenotypic evolution. Gene-expression signatures of good and poor prognosis were detected in different regions of the same tumor. Allelic composition and ploidy profiling analysis revealed extensive intratumor heterogeneity, with 26 of 30 tumor samples from four tumors harboring divergent allelic-imbalance profiles and with ploidy heterogeneity in two of four tumors. Conclusions Intratumor heterogeneity can lead to underestimation of the tumor genomics landscape portrayed from single tumor-biopsy samples and may present major challenges to personalized-medicine and biomarker development. Intratumor heterogeneity, associated with heterogeneous protein function, may foster tumor adaptation and therapeutic failure through Darwinian selection. (Funded by the Medical Research Council and others.)

Circulating Tumor Cells, Disease Progression, and Survival in Metastatic Breast Cancer

Abstract: Metastatic breast cancer (MBC) is considered incurable; therefore, palliative treatment is the only option. The biologic heterogeneity of the disease is reflected in its somewhat unpredictable clinical behavior. The presence of circulating tumor cells (CTCs) in patients with MBC about to start a new line of treatment has been shown to predict progression-free and overall survival. This prognostic value is independent of the line of therapy (eg, first or second line). Moreover, a multivariate analysis has shown the prognostic value of CTCs to be superior to that of site of metastasis, type of therapy, and length of time to recurrence after definitive primary surgery. These data suggest that the presence of CTCs may be used to modify the staging system for advanced disease. Larger studies are needed to confirm these data and evaluate the use of CTC detection in monitoring treatment and furthering our understanding of breast cancer biology when combined with other diagnostic technologies.

Hematopoietic Stem-Cell Transplantation

Abstract: Hematopoietic stem-cell transplantation, which is used to treat both malignant and nonmalignant conditions, was first conceived more than 50 years ago, but problems associated with transplanting a nonsolid organ and modulating the immune response had to be solved before the procedure could be used clinically. This review summarizes background information about hematopoietic stem-cell transplantation and discusses the current role of the procedure.