PURPOSE: Limited tools exist to predict the risk of chemotherapy toxicity in older adults with early-stage breast cancer. METHODS: Patients of age ≥ 65 years with stage I-III breast cancer from 16 institutions treated with neoadjuvant or adjuvant chemotherapy were prospectively evaluated for geriatric and clinical features predictive of grade 3-5 chemotherapy toxicity. Logistic regression with best-subsets selection was used to identify and incorporate independent predictors of toxicity into a model with weighted variable scoring. Model performance was evaluated using area under the ROC curve (AUC) and goodness-of-fit statistics. The model was internally and externally validated. RESULTS: In 473 patients (283 in development and 190 in validation cohort), 46% developed grade 3-5 chemotherapy toxicities. Eight independent predictors were identified (each assigned weighted points): anthracycline use (1 point), stage II or III (3 points), planned treatment duration > 3 months (4 points), abnormal liver function (3 points), low hemoglobin (3 points), falls (4 points), limited walking (3 points), and lack of social support (3 points). We calculated risk scores for each patient and defined three risk groups: low (0-5 points), intermediate (6-11 points), or high (≥ 12 points). In the development cohort, the rates of grade 3-5 chemotherapy toxicity for these three groups were 19%, 54%, and 87%, respectively ( P < .01). In the validation cohort, the corresponding toxicity rates were 27%, 45%, and 76%. The AUC was 0.75 (95% CI, 0.70 to 0.81) in the development cohort and 0.69 (95% CI, 0.62 to 0.77) in the validation cohort. Risk groups were also associated with hospitalizations and reduced dose intensity ( P < .01). CONCLUSION: The Cancer and Aging Research Group-Breast Cancer (CARG-BC) score was developed and validated to predict grade 3-5 chemotherapy toxicity in older adults with early-stage breast cancer.

Purpose: The objectives were to evaluate dosing schedules of labetuzumab govitecan, an antibody-drug conjugate targeting carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) for tumor delivery of 7-ethyl-10-hydroxycamptothecin (SN-38), in an expanded phase II trial of patients with relapsed or refractory metastatic colorectal cancer. Patients and Methods: Eligible patients with at least one prior irinotecan-containing therapy received labetuzumab govitecan once weekly at 8 and 10 mg/kg, or two times per week at 4 and 6 mg/km on weeks 1 and 2 of 3-week repeated cycles. End points were safety, response, pharmacokinetics, and immunogenicity. Results: Eighty-six patients who had undergone a median of five prior therapies (range, one to 13) were each enrolled into one of the four cohorts. On the basis of Response Evaluation Criteria in Solid Tumors 1.1, 38% of these patients had a tumor as well as plasma carcinoembryonic antigen reduction from baseline after labetuzumab govitecan treatment; one patient achieved a partial response with a sustained response spanning > 2 years, whereas 42 patients had stable disease as the best overall response. Median progression-free survival and overall survival were 3.6 and 6.9 months, respectively. The major toxicities (grade ≥ 3) among all cohorts were neutropenia (16%), leukopenia (11%), anemia (9%), and diarrhea (7%). The antibody-drug conjugate’s mean half-life was 16.5 hours for the four cohorts. Anti-drug/anti-antibody antibodies were not detected. The two once-weekly dose schedules, showing comparable toxicity and efficacy, were chosen for further study. Conclusion: Monotherapy with labetuzumab govitecan demonstrated a manageable safety profile and therapeutic activity in heavily pretreated patients with metastatic colorectal cancer, all with prior irinotecan therapy. Further studies of labetuzumab govitecan treatment alone or in combination with other therapies in earlier settings are indicated.

Circulating tumor DNA (ctDNA) is a component of cell-free DNA (cfDNA) that is shed by malignant tumors into the bloodstream and other bodily fluids. ctDNA can comprise up to 10% of a patient’s cfDNA depending on their tumor type and burden. The short half-life of ctDNA ensures that its detection captures tumor burden in real-time and offers a non-invasive method of repeatedly evaluating the genomic profile of a patient’s tumor. A challenge in ctDNA detection includes clonal hematopoiesis of indeterminate potential (CHIP), which can be distinguished from tumor variants using a paired whole-blood control. Most assays for ctDNA quantification rely on measurements of somatic variant allele frequency (VAF), which is a mutation-dependent method. Patients with certain types of solid tumors, including colorectal cancer (CRC), can have levels of cfDNA 50 times higher than healthy patients. ctDNA undergoes a precipitous drop shortly after tumor resection and therapy, and rising levels can foreshadow radiologic recurrence on the order of months. The amount of tumor bulk required for ctDNA detection is lower than that for computed tomography (CT) scan detection, with ctDNA detection preceding radiologic recurrence in many cases. cfDNA/ctDNA can be used for tumor molecular profiling to identify resistance mutations when tumor biopsy is not available, to detect minimal residual disease (MRD), to monitor therapy response, and for the detection of tumor relapse. Although ctDNA is not yet implemented in clinical practice, studies are ongoing to define the appropriate way to use it as a tool in the clinic. In this review article, we examine the general aspects of ctDNA, its status as a biomarker, and its role in the management of early (II–III) and late (IV; mCRC) stage colorectal cancer (CRC).

Purpose: The recombinant fusion protein ipafricept blocks Wnt signaling, and in combination with gemcitabine and nab-paclitaxel caused tumor regression in xenografts. This phase Ib study evaluated the combination of ipafricept with nab-paclitaxel + gemcitabine in patients with untreated metastatic pancreatic adenocarcinoma (mPDAC). Patients and Methods: Dose escalation started with standard dose nab-paclitaxel + gemcitabine and ipafricept (3.5 mg/kg days 1, 15). Because of fragility fractures seen with different anti-Wnt agents, following cohorts had ≥6 patients treated with ipafricept 3 to 5 mg/kg on day 1, and included bone marker monitoring and prophylactic bisphosphonates as indicated. On the basis of preclinical data, sequential dosing was evaluated in cohort 4 (ipafricept day 1 followed nab-paclitaxel + gemcitabine day 3). Objectives included safety, MTD, recommended phase II dose, pharmacokinetics, immunogenicity, pharmacodynamics, and efficacy. Results: A total of 26 patients were enrolled, five in cohort 1 and seven each in cohorts 2–4. ipafricept-related adverse events (AEs) of any grade included fatigue, nausea, vomiting, anorexia, and pyrexia. ipafricept-related AEs grade ≥3 included two events of aspartate aminotransferase elevation, and one each of nausea, rash, vomiting, and leucopenia. No dose-limiting toxicities or fragility fractures were observed. Nine patients (34.6%) had partial response, 12 (46.2%) stable disease as best response, with clinical benefit rate of 81%. Median progression-free survival was 5.9 m [95% confidence interval (CI), 3.4–18.4], median overall survival was 9.7 m (95% CI, 7.0–14). The study was terminated by the sponsor due to bone-related toxicity within this therapeutic program and concerns for commercial viability. One patient remains on therapy under compassionate use. Conclusions: Ipafricept can be administered with nab-paclitaxel + gemcitabine with reasonable tolerance. Wnt pathway remains a therapeutic target of interest in mPDAC.

Objectives Development of targeted therapies for pancreatic cancer could be enhanced by a reliable method for noninvasive tumor cell assessment. In this pilot study, we isolated and phenotypically characterized circulating tumor cells (CTCs) from patients with metastatic pancreatic cancer and explored their relationship to clinical outcome. Methods Peripheral blood from 50 patients was collected at treatment initiation and first disease evaluation for CTC enumeration and phenotyping by CellSearch® system. Expression of human mucin 1 (MUC-1) was performed. Results Forty-eight and 37 patients had evaluable samples at baseline and first disease evaluation, respectively. The cohort was 62% male, with a median age of 63 years. At least 1 CTC per 7.5 mL was detected in 23 patients (48%) pretreatment and 11 patients (30%) at first disease evaluation. No difference was seen in overall survival between patients with 1 or more CTCs versus no CTC at baseline (P = 0.14). Patients with MUC-1 expressing CTC (n = 10) had shorter median overall survival compared with those with MUC-1 negative CTC (n = 13; 2.7 vs 9.6 m; P = 0.044). Conclusions Circulating tumor cell enumeration and phenotypic characterization from metastatic pancreatic cancer patients are feasible. No correlation was found between CTC isolation and survival. However, the presence of MUC-1 expressing CTC demonstrated a trend toward inferior survival.