Outcomes on anti-VEGFR-2/paclitaxel treatment after progression on immune checkpoint inhibition in patients with metastatic gastroesophageal adenocarcinoma.

Through our involvement in KEYNOTE-059, we unexpectedly observed durable responses in two patients with metastatic gastroesophageal adenocarcinoma (mGEA) who received ramucirumab (anti-VEGFR-2)/paclitaxel after immune checkpoint inhibition (ICI). To assess the reproducibility of this observation, we piloted an approach to administer ramucirumab/paclitaxel after ICI in more patients, and explored changes in the immune microenvironment. Nineteen consecutive patients with mGEA received ICI followed by ramucirumab/paclitaxel. Most (95%) did not respond to ICI, yet after irRECIST-defined progression on ICI, all patients experienced tumor size reduction on ramucirumab/paclitaxel. The objective response rate (ORR) and progression-free survival (PFS) on ramucirumab/paclitaxel after ICI were higher than on the last chemotherapy before ICI in the same group of patients (ORR, 58.8% vs 11.8%; PFS 12.2 vs 3.0 months; respectively). Paired tumor biopsies examined by imaging mass cytometry showed a median 5.5-fold (range 4-121) lower frequency of immunosuppressive forkhead box P3+ regulatory T cells with relatively preserved CD8+ T cells, post-treatment versus pre-treatment (n = 5 pairs). We then compared the outcomes of these 19 patients with a separate group who received ramucirumab/paclitaxel without preceding ICI (n = 68). Median overall survival on ramucirumab/paclitaxel was longer with (vs without) immediately preceding ICI (14.8 vs 7.4 months) including after multivariate analysis, as was PFS. In our small clinical series, outcomes appeared improved on anti-VEGFR-2/paclitaxel treatment when preceded by ICI, in association with alterations in the immune microenvironment. However, further investigation is needed to determine the generalizability of these data. Prospective clinical trials to evaluate sequential treatment with ICI followed by anti-VEGF(R)/taxane are underway.

Nanoliposomal irinotecan (Nal-IRI)-based chemotherapy after irinotecan -based chemotherapy in patients with pancreas cancer.

BACKGROUND: Nanoliposomal irinotecan (Nal-IRI) is a preferred second-line treatment for metastatic pancreas cancer. It is unclear, however, whether patients who had received irinotecan derive benefit. METHODS: Medical records of metastatic pancreas cancer patients who had received irinotecan and then Nal-IRI were reviewed. The primary endpoint was overall survival after the initiation of Nal-IRI (an a priori threshold of >4 months defined success); adverse events and quotes from the medical record on decision-making were also recorded. RESULTS: Sixty four patients met eligibility criteria with a median age of 65 years (range: 36, 80 years). The median overall survival from initiation of Nal-IRI was 5.1 months (95% confidence interval (CI): 4.3, 5.6 months). An exploratory comparison, based on no cancer progression with irinotecan versus progression, showed improved survival with Nal-IRI in the former group: 6.1 months (95% CI: 5.1, 9.3 months) versus 4.3 months (95% CI: 2.3, 4.8 months); p = 0.0006. Nal-IRI adverse events occurred as expected. Qualitative data illustrate several themes, including "limited treatment options," which appeared to drive the decision to prescribe Nal-IRI. CONCLUSION: Nal-IRI might be considered in pancreas cancer patients who had received irinotecan, particularly in the absence of disease progression with the latter.

Falls: descriptive rates and circumstances in age-unspecified patients with locally advanced esophageal cancer.

PURPOSE: Falls can occur in older cancer patients, but few studies have examined falls in an age-unspecified group of patients with locally advanced esophageal cancer. Because these patients are often administered neuropathy-inducing agents, are weak, and can develop orthostatic symptoms, examining falls appears relevant. METHODS: Electronic medical records were used to examine falls and their circumstances in locally advanced esophageal cancer patients treated with chemotherapy and radiation and often surgery. RESULTS: Among 300 patients, 62 (21%) suffered a fall, yielding 6 falls per 100 patient years. The median age at first fall was 64 years (range 31 to 83). The median time from cancer diagnosis to first fall was 11 months (range 0 to 107). Forty-two patients (68%) who fell had active cancer; 20 (32%) were cancer-free. Fall-related injuries occurred in 42 patients and included fractures, hematomas, and other musculoskeletal events. Eighteen patients (29%) fell repeatedly. Neuropathy, general weakness, and orthostatic symptoms were associated with falls ("He does state his neuropathy is more bothersome…. He did have a fall last week…." "He has been increasingly weak to the point where he fell down last week…." "Upon rising… [he] felt like somebody had put a sheet over his eyes, felt very lightheaded, and fell to the floor…."). At times, falls occurred under commonplace circumstances, such as slipping on ice or tripping on an underfoot pet. CONCLUSION: Regardless of patient age, clinicians should remain vigilant for fall risk in adult patients with locally advanced esophageal cancer.

Phase 1 trial of Vismodegib and Erlotinib combination in metastatic pancreatic cancer.

BACKGROUND/OBJECTIVES: Interplay between the Hedgehog (HH) and epidermal growth factor receptor (EGFR) pathways modulating the outcome of their signaling activity have been reported in various cancers including pancreatic ductal adenocarcinoma (PDAC). Therefore, simultaneous targeting of these pathways may be clinically beneficial. This Phase I study combined HH and EGFR inhibition in metastatic PDAC patients. METHODS: Combined effects of HH and EGFR inhibition using Vismodegib and Erlotinib with or without gemcitabine in metastatic solid tumors were assessed by CT. Another cohort of patients with metastatic PDAC was evaluated by FDG-PET and tumor biopsies-derived biomarkers. RESULTS: Treatment was well tolerated with the maximum tolerated dose cohort experiencing no grade 4 toxicities though 25% experienced grade 3 adverse effects. Recommended phase II dose of Vismodegib and Erlotinib were each 150 mg daily. No tumor responses were observed although 16 patients achieved stable disease for 2-7 cycles. Paired biopsy analysis before and after first cycle of therapy in PDAC patients showed reduced GLI1 mRNA, phospho-GLI1 and associated HH target genes in all cases. However, only half of the cases showed reduced levels of desmoplasia or changes in fibroblast markers. Most patients had decreased phospho-EGFR levels. CONCLUSIONS: Vismodegib and Erlotinib combination was well-tolerated although overall outcome in patients with metastatic PDAC was not significantly impacted by combination treatment. Biomarker analysis suggests direct targets inhibition without significantly affecting the stromal compartment. These findings conflict with pre-clinical mouse models, and thus warrant further investigation into how upstream inhibition of these pathways is circumvented in PDAC.

Role of Ultraviolet Radiation in Papillomavirus-Induced Disease.

Human papillomaviruses are causally associated with 5% of human cancers. The recent discovery of a papillomavirus (MmuPV1) that infects laboratory mice provides unique opportunities to study the life cycle and pathogenesis of papillomaviruses in the context of a genetically manipulatable host organism. To date, MmuPV1-induced disease has been found largely to be restricted to severely immunodeficient strains of mice. In this study, we report that ultraviolet radiation (UVR), specifically UVB spectra, causes wild-type strains of mice to become highly susceptible to MmuPV1-induced disease. MmuPV1-infected mice treated with UVB develop warts that progress to squamous cell carcinoma. Our studies further indicate that UVB induces systemic immunosuppression in mice that correlates with susceptibility to MmuPV1-associated disease. These findings provide new insight into how MmuPV1 can be used to study the life cycle of papillomaviruses and their role in carcinogenesis, the role of host immunity in controlling papillomavirus-associated pathogenesis, and a basis for understanding in part the role of UVR in promoting HPV infection in humans.

Whole Blood mRNA Expression-Based Prognosis of Metastatic Renal Cell Carcinoma.

The Memorial Sloan Kettering Cancer Center (MSKCC) prognostic score is based on clinical parameters. We analyzed whole blood mRNA expression in metastatic clear cell renal cell carcinoma (mCCRCC) patients and compared it to the MSKCC score for predicting overall survival. In a discovery set of 19 patients with mRCC, we performed whole transcriptome RNA sequencing and selected eighteen candidate genes for further evaluation based on associations with overall survival and statistical significance. In an independent validation of set of 47 patients with mCCRCC, transcript expression of the 18 candidate genes were quantified using a customized NanoString probeset. Cox regression multivariate analysis confirmed that two of the candidate genes were significantly associated with overall survival. Higher expression of BAG1 [hazard ratio (HR) of 0.14, p < 0.0001, 95% confidence interval (CI) 0.04-0.36] and NOP56 (HR 0.13, p < 0.0001, 95% CI 0.05-0.34) were associated with better prognosis. A prognostic model incorporating expression of BAG1 and NOP56 into the MSKCC score improved prognostication significantly over a model using the MSKCC prognostic score only (p < 0.0001). Prognostic value of using whole blood mRNA gene profiling in mCCRCC is feasible and should be prospectively confirmed in larger studies.

Safety and activity of anti-PD-L1 antibody in patients with advanced cancer.

BACKGROUND: Programmed death 1 (PD-1) protein, a T-cell coinhibitory receptor, and one of its ligands, PD-L1, play a pivotal role in the ability of tumor cells to evade the host's immune system. Blockade of interactions between PD-1 and PD-L1 enhances immune function in vitro and mediates antitumor activity in preclinical models. METHODS: In this multicenter phase 1 trial, we administered intravenous anti-PD-L1 antibody (at escalating doses ranging from 0.3 to 10 mg per kilogram of body weight) to patients with selected advanced cancers. Anti-PD-L1 antibody was administered every 14 days in 6-week cycles for up to 16 cycles or until the patient had a complete response or confirmed disease progression. RESULTS: As of February 24, 2012, a total of 207 patients--75 with non-small-cell lung cancer, 55 with melanoma, 18 with colorectal cancer, 17 with renal-cell cancer, 17 with ovarian cancer, 14 with pancreatic cancer, 7 with gastric cancer, and 4 with breast cancer--had received anti-PD-L1 antibody. The median duration of therapy was 12 weeks (range, 2 to 111). Grade 3 or 4 toxic effects that investigators considered to be related to treatment occurred in 9% of patients. Among patients with a response that could be evaluated, an objective response (a complete or partial response) was observed in 9 of 52 patients with melanoma, 2 of 17 with renal-cell cancer, 5 of 49 with non-small-cell lung cancer, and 1 of 17 with ovarian cancer. Responses lasted for 1 year or more in 8 of 16 patients with at least 1 year of follow-up. CONCLUSIONS: Antibody-mediated blockade of PD-L1 induced durable tumor regression (objective response rate of 6 to 17%) and prolonged stabilization of disease (rates of 12 to 41% at 24 weeks) in patients with advanced cancers, including non-small-cell lung cancer, melanoma, and renal-cell cancer. (Funded by Bristol-Myers Squibb and others; ClinicalTrials.gov number, NCT00729664.).

A Randomized Controlled Trial of Fluorouracil Plus Leucovorin, Irinotecan, and Oxaliplatin Combinations in Patients With Previously Untreated Metastatic Colorectal Cancer.

PURPOSE: Three agents with differing mechanisms of action are available for treatment of advanced colorectal cancer: fluorouracil, irinotecan, and oxaliplatin. In this study, we compared the activity and toxicity of three different two-drug combinations in patients with metastatic colorectal cancer who had not been treated previously for advanced disease. PATIENTS AND METHODS: Patients were concurrently randomly assigned to receive irinotecan and bolus fluorouracil plus leucovorin (IFL, control combination), oxaliplatin and infused fluorouracil plus leucovorin (FOLFOX), or irinotecan and oxaliplatin (IROX). The primary end point was time to progression, with secondary end points of response rate, survival time, and toxicity. RESULTS: A total of 795 patients were randomly assigned between May 1999 and April 2001. A median time to progression of 8.7 months, response rate of 45%, and median survival time of 19.5 months were observed for FOLFOX. These results were significantly superior to those observed for IFL for all end points (6.9 months, 31%, and 15.0 months, respectively) or for IROX (6.5 months, 35%, and 17.4 months, respectively) for time to progression and response. The FOLFOX regimen had significantly lower rates of severe nausea, vomiting, diarrhea, febrile neutropenia, and dehydration. Sensory neuropathy and neutropenia were more common with the regimens containing oxaliplatin. CONCLUSION: The FOLFOX regimen of oxaliplatin and infused fluorouracil plus leucovorin was active and comparatively safe. It should be considered as a standard therapy for patients with advanced colorectal cancer.

Resection of a Solitary Right Ventricular Metastasis in Oligorecurrent Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC), constituting the predominant manifestation of liver cancer, stands as a formidable medical challenge. The prognosis subsequent to surgical intervention, particularly for individuals presenting with a solitary tumor, relies heavily on the degree of invasiveness. The decision-making process surrounding therapeutic modalities in such cases assumes paramount importance. This case report illuminates a rather unusual clinical scenario. Here, we encounter a patient who, following a disease-free interval, manifested an atypical presentation of HCC, specifically, a solitary cardiac metastasis. The temporal interval of remission adds an additional layer of complexity to the case. Through a multidisciplinary planning process, the decision was made for surgical removal of the metastatic tumor.

Phase 2 study of bevacizumab plus erlotinib in patients with advanced hepatocellular cancer.

BACKGROUND: Epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) are rational targets for therapy in hepatocellular cancer (HCC). METHODS: Patients with histologically proven HCC and not amenable to curative or liver directed therapy were included in this 2-stage phase 2 trial. Eligibility included an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1 and Child's Pugh score of A or B, and 1 prior systemic therapy. Patients received erlotinib 150 mg daily and bevacizumab 10 mg/kg on days 1 and 15 every 28 days. Objective tumor response was the primary end point. RESULTS: Twenty-seven patients with advanced HCC (median age, 60 years) were enrolled in this multi-institutional study. The proportion of patients with Child's A classification was 74%. One patient had a confirmed partial response and 11 (48%) achieved stable disease. Median time to disease progression was 3.0 months (95% confidence interval [CI], 1.8-7.1). Median survival time was 9.5 months (95% CI, 7.1-17.1). Grade 3 toxicities included rash, hypertension, fatigue, and diarrhea. CONCLUSIONS: In this trial, erlotinib combined with bevacizumab had minimal activity in patients with advanced HCC based on objective response and progression-free survival. The role of targeting EGFR and VEGF in HCC needs further evaluation in molecularly selected patients.

An international, multicenter phase II trial of bortezomib in patients with hepatocellular carcinoma.

BACKGROUND AND RATIONALE: Bortezomib (PS-341, VELCADE®) is a selective inhibitor of the 26S proteasome, an integral component of the ubiquitin-proteasome pathway. This phase II study evaluated the activity and tolerability of bortezomib in unresectable hepatocellular carcinoma (HCC) patients. METHODS: The primary endpoint was confirmed tumor response rate (RR) with secondary endpoints including duration of response, time to disease progression, survival and toxicity. Treatment consisted of bortezomib, 1.3 mg/m2 IV bolus on days 1, 4, 8, and 11 of each 21-day treatment cycle. Eligibility included: no prior systemic chemotherapy, ECOG PS 0-2, Child-Pugh A or B, preserved hematologic, hepatic and neurologic function; prior liver-directed therapy was permitted. RESULTS: Thirty-five patients enrolled and received a median of 2 cycles of treatment (range 1-12). Overall, 24 and 4 patients had a maximum severity of grade 3 and 4 adverse events (AEs), respectively. No treatment related deaths occurred. Only thrombocytopenia (11%) was seen in greater than 10% of patients. One patient achieved a partial response, lasting 13 weeks during treatment and progressed 11.6 months later; two patients received treatment for greater than 6 months. Median time-to-progression was 1.6 months and median survival was 6.0 months. CONCLUSIONS: This international, multicenter trial evaluated bortezomib as monotherapy in unresectable HCC patients. And, despite the lack of significant activity, this report serves as a baseline clinical experience for the development of future dual biologic approaches including bortezomib.

Pembrolizumab in Combination with Neoadjuvant Chemoradiotherapy for Patients with Resectable Adenocarcinoma of the Gastroesophageal Junction.

PURPOSE: This phase Ib/2 trial investigated pembrolizumab-containing trimodality therapy in patients with gastroesophageal junction (GEJ) adenocarcinoma. PATIENTS AND METHODS: Patients with GEJ adenocarcinoma (cT1-3NanyM0) received neoadjuvant pembrolizumab-containing chemoradiation (CROSS regimen) followed by surgical resection and adjuvant pembrolizumab. The primary endpoints were tolerability in the first 16 patients and pathologic complete response [pCR (ypT0N0)]. Secondary endpoints included progression-free survival (PFS) and overall survival (OS). An independent propensity-score-matched cohort (treated with CROSS without immunotherapy) was used for comparison. Exploratory analyses included immune biomarkers in the tumor microenvironment (TME) and plasma. RESULTS: We enrolled 31 eligible patients, of whom 29 received all expected doses of neoadjuvant pembrolizumab and 28 underwent R0 resection. Safety endpoints were met. The primary efficacy endpoint was not met [7/31 (22.6%) achieved pCR]. Patients with high [i.e., combined positive score (CPS) ≥ 10] baseline expression of programmed death (PD)-L1 in the TME had a significantly higher pCR rate than those with low expression [50.0% (4/8) vs. 13.6% (3/22); P = 0.046]. Patients with high PD-L1 expression also experienced longer PFS and OS than propensity-score-matched patients. Among trial patients with PD-L1 CPS < 10, unprespecified analysis explored whether extracellular vesicles (EV) could identify further responders: an elevated plasma level of PD-L1-expressing EVs was significantly associated with higher pCR. CONCLUSIONS: Adding pembrolizumab to trimodality therapy showed acceptable tolerability but did not meet the pre-specified pCR endpoint. Exploratory analyses suggested that high PD-L1 expression in the TME and/or on EVs may identify patients most likely to achieve tumor response.

Metastatic Colorectal Cancer Outcomes by Age Among ARCAD First- and Second-Line Clinical Trials.

BACKGROUND: We evaluated the time to progression (TTP) and survival outcomes of second-line therapy for metastatic colorectal cancer among adults aged 70 years and older compared with younger adults following progression on first-line clinical trials. METHODS: Associations between clinical and disease characteristics, time to initial progression, and rate of receipt of second-line therapy were evaluated. TTP and overall survival (OS) were compared between older and younger adults in first- and second-line trials by Cox regression, adjusting for age, sex, Eastern Cooperative Oncology Group Performance Status, number of metastatic sites and presence of metastasis in the lung, liver, or peritoneum. All statistical tests were 2-sided. RESULTS: Older adults comprised 16.4% of patients on first-line trials (870 total older adults aged >70 years; 4419 total younger adults aged ≤70 years, on first-line trials). Older adults and those with Eastern Cooperative Oncology Group Performance Status >0 were less likely to receive second-line therapy than younger adults. Odds of receiving second-line therapy decreased by 11% for each additional decade of life in multivariable analysis (odds ratio = 1.11, 95% confidence interval = 1.02 to 1.21, P = .01). Older and younger adults enrolled in second-line trials experienced similar median TTP and median OS (median TTP = 5.1 vs 5.2 months, respectively; median OS = 11.6 vs 12.4 months, respectively). CONCLUSIONS: Older adults were less likely to receive second-line therapy for metastatic colorectal cancer, though we did not observe a statistical difference in survival outcomes vs younger adults following second-line therapy. Further study should examine factors affecting decisions to treat older adults with second-line therapy. Inclusion of geriatric assessment may provide better criteria regarding the risks and benefits of second-line therapy.

Estrogen Receptor-α Suppresses Liver Carcinogenesis and Establishes Sex-Specific Gene Expression.

Estrogen protects females from hepatocellular carcinoma (HCC). To determine whether this protection is mediated by classic estrogen receptors, we tested HCC susceptibility in estrogen receptor-deficient mice. In contrast to a previous study, we found that diethylnitrosamine induces hepatocarcinogenesis to a significantly greater extent when females lack Esr1, which encodes Estrogen Receptor-α. Relative to wild-type littermates, Esr1 knockout females developed 9-fold more tumors. Deficiency of Esr2, which encodes Estrogen Receptor-ß, did not affect liver carcinogenesis in females. Using microarrays and QPCR to examine estrogen receptor effects on hepatic gene expression patterns, we found that germline Esr1 deficiency resulted in the masculinization of gene expression in the female liver. Six of the most dysregulated genes have previously been implicated in HCC. In contrast, Esr1 deletion specifically in hepatocytes of Esr1 conditional null female mice (in which Cre was expressed from the albumin promoter) resulted in the maintenance of female-specific liver gene expression. Wild-type adult females lacking ovarian estrogen due to ovariectomy, which is known to make females susceptible to HCC, also maintained female-specific expression in the liver of females. These studies indicate that Esr1 mediates liver cancer risk, and its control of sex-specific liver gene expression involves cells other than hepatocytes.

Predominant modifier of extreme liver cancer susceptibility in C57BR/cdJ female mice localized to 6 Mb on chromosome 17.

Sex hormones influence the susceptibility of inbred mice to liver cancer. C57BR/cdJ (BR) females are extremely susceptible to spontaneous and chemically induced liver tumors, in part due to a lack of protection against hepatocarcinogenesis normally offered by ovarian hormones. BR males are also moderately susceptible, and the susceptibility of both sexes of BR mice to liver tumors induced with N,N-diethylnitrosamine relative to the resistant C57BL/6J (B6) strain is caused by two loci designated Hcf1 and Hcf2 (hepatocarcinogenesis in females) located on chromosomes 17 and 1, respectively. The Hcf1 locus on chromosome 17 is the predominant modifier of liver cancer in BR mice. To validate the existence of this locus and investigate its potential interaction with Hcf2, congenic mice for each region were generated. Homozygosity for the B6.BR(D17Mit164-D17Mit2) region resulted in a 4-fold increase in liver tumor multiplicity in females and a 4.5-fold increase in males compared with B6 controls. A series of 16 recombinants covering the entire congenic region was developed to further narrow the area containing Hcf1. Susceptible heterozygous recombinants demonstrated a 3- to 7-fold effect in females and a 1.5- to 2-fold effect in males compared with B6 siblings. The effect in susceptible lines completely recapitulated the susceptibility of heterozygous full-length chromosome 17 congenics and furthermore narrowed the location of the Hcf1 locus to a single region of the chromosome from 30.05 to 35.83 Mb.

Disruption of estrogen receptor signaling enhances intestinal neoplasia in Apc(Min/+) mice.

Estrogen receptors (ERs) [ERalpha (Esr1) and ERbeta (Esr2)] are expressed in the human colon, but during the multistep process of colorectal carcinogenesis, expression of both ERalpha and ERbeta is lost, suggesting that loss of ER function might promote colorectal carcinogenesis. Through crosses between an ERalpha knockout and Apc(Min) mouse strains, we demonstrate that ERalpha deficiency is associated with a significant increase in intestinal tumor multiplicity, size and burden in Apc(Min/+) mice. Within the normal intestinal epithelium of Apc(Min/+) mice, ERalpha deficiency is associated with an accumulation of nuclear beta-catenin, an indicator of activation of the Wnt-beta-catenin-signaling pathway, which is known to play a critical role in intestinal cancers. Consistent with the hypothesis that ERalpha deficiency is associated with activation of Wnt-beta-catenin signaling, ERalpha deficiency in the intestinal epithelium of Apc(Min/+) mice also correlated with increased expression of Wnt-beta-catenin target genes. Through crosses between an ERbeta knockout and Apc(Min) mouse strains, we observed some evidence that ERbeta deficiency is associated with an increased incidence of colon tumors in Apc(Min/+) mice. This effect of ERbeta deficiency does not involve modulation of Wnt-beta-catenin signaling. Our studies suggest that ERalpha and ERbeta signaling modulate colorectal carcinogenesis, and ERalpha does so, at least in part, by regulating the activity of the Wnt-beta-catenin pathway.

The pleiotropic phenotype of Apc mutations in the mouse: allele specificity and effects of the genetic background.

Familial adenomatous polyposis (FAP) is a human cancer syndrome characterized by the development of hundreds to thousands of colonic polyps and extracolonic lesions including desmoid fibromas, osteomas, epidermoid cysts, and congenital hypertrophy of the pigmented retinal epithelium. Afflicted individuals are heterozygous for mutations in the APC gene. Detailed investigations of mice heterozygous for mutations in the ortholog Apc have shown that other genetic factors strongly influence the phenotype. Here we report qualitative and quantitative modifications of the phenotype of Apc mutants as a function of three genetic variables: Apc allele, p53 allele, and genetic background. We have found major differences between the Apc alleles Min and 1638N in multiplicity and regionality of intestinal tumors, as well as in incidence of extracolonic lesions. By contrast, Min mice homozygous for either of two different knockout alleles of p53 show similar phenotypic effects. These studies illustrate the classic principle that functional genetics is enriched by assessing penetrance and expressivity with allelic series. The mouse permits study of an allelic gene series on multiple genetic backgrounds, thereby leading to a better understanding of gene action in a range of biological processes.

Plasma insulin-like growth factors, insulin-like binding protein-3, and outcome in metastatic colorectal cancer: results from intergroup trial N9741.

PURPOSE: Insulin-like growth factor (IGF)-I and IGF-II stimulate neoplastic cell growth and inhibit apoptosis, whereas IGF-binding protein-3 (IGFBP-3) inhibits the bioavailability of IGF-I and has independent proapoptotic activity. We examined the influence of baseline plasma levels of IGF-I, IGF-II, IGFBP-3, and C-peptide on outcome among patients receiving first-line chemotherapy for metastatic colorectal cancer. EXPERIMENTAL DESIGN: The plasma levels of IGF-I, IGF-II, IGFBP-3, and C-peptide as well as data on prognostic factors and body size were measured at baseline among 527 patients participating in a randomized trial of first-line chemotherapy for metastatic colorectal cancer. RESULTS: Higher baseline plasma IGFBP-3 levels were associated with a significantly greater chemotherapy response rate (P = 0.03) after adjusting for other prognostic factors, whereas neither IGF-I nor IGF-II levels significantly predicted tumor response. Higher levels of IGF-I, IGF-II, and IGFBP-3 were all univariately associated with improved overall survival (P = 0.0001 for all). In a model that mutually adjusted for IGF-I and IGFBP-3, as well as other prognostic factors, increasing baseline-circulating IGFBP-3 was associated with a significantly longer time to tumor progression (P = 0.03), whereas circulating IGF-I was not associated with disease progression (P = 0.95). Levels of C-peptide were not associated with any measure of patient outcome. CONCLUSION: Among colorectal cancer patients receiving first-line chemotherapy, increasing levels of IGFBP-3, an endogenous antagonist to IGF-I, are associated with an improved objective treatment response and a prolonged time to cancer progression. The IGF pathway may represent an important target for future treatment strategies.

A phase II trial of 17-allylamino-17-demethoxygeldanamycin in patients with hormone-refractory metastatic prostate cancer.

PURPOSE: 17-Allylamino-17-demethoxygeldanamycin (17-AAG) is a benzoquinone ansamycin antibiotic with antiproliferative activity in several mouse xenograft models, including prostate cancer models. A two-stage phase II study was conducted to assess the activity and toxicity profile of 17-AAG administered to patients with metastatic, hormone-refractory prostate cancer. EXPERIMENTAL DESIGN: Patients with at least one prior systemic therapy and a rising prostate-specific antigen (PSA) were eligible. Patients received 17-AAG at a dose of 300 mg/m2 i.v. weekly for 3 of 4 weeks. The primary objective was to assess the PSA response. Secondary objectives were to determine overall survival, to assess toxicity, and to measure interleukin-6, interleukin-8, and maspin levels and quality of life. RESULTS: Fifteen eligible patients were enrolled. The median age was 68 years and the median PSA was 261 ng/mL. Patients received 17-AAG for a median number of two cycles. Severe adverse events included grade 3 fatigue (four patients), grade 3 lymphopenia (two patients), and grade 3 back pain (two patients). The median PSA progression-free survival was 1.8 months (95% confidence interval, 1.3-3.4 months). The 6-month overall survival was 71% (95% confidence interval, 52-100%). CONCLUSIONS: 17-AAG did not show any activity with regard to PSA response. Due to insufficient PSA response, enrollment was stopped at the end of first stage per study design. The most significant severe toxicity was grade 3 fatigue. Further evaluation of 17-AAG at a dose of 300 mg/m2 i.v. weekly as a single agent in patients with metastatic, hormone-refractory prostate cancer who received at least one prior systemic therapy is not warranted.