Molecular Heterogeneity and Response to Neoadjuvant Human Epidermal Growth Factor Receptor 2 Targeting in CALGB 40601, a Randomized Phase III Trial of Paclitaxel Plus Trastuzumab With or Without Lapatinib

Dual human epidermal growth factor receptor 2 (HER2) targeting can increase pathologic complete response rates (pCRs) to neoadjuvant therapy and improve progression-free survival in metastatic disease. CALGB 40601 examined the impact of dual HER2 blockade consisting of trastuzumab and lapatinib added to paclitaxel, considering tumor and microenvironment molecular features

Assessment of Perceived Cost to the Patient and Other Barriers to Clinical Trial Participation

Concerns about adverse effects and random assignment were the most common reasons cited by patients declining trial participation in four community oncology practices in New England

Effect of High-Dose vs Standard-Dose Vitamin D3 Supplementation on Body Composition among Patients with Advanced or Metastatic Colorectal Cancer: A Randomized Trial

Skeletal muscle and adipose tissue express the vitamin D receptor and may be a mechanism through which vitamin D supplementation slows cancer progression and reduces cancer death. In this exploratory analysis of a double-blind, multicenter, randomized phase II clinical trial, 105 patients with advanced or metastatic colorectal cancer who were receiving chemotherapy were randomized to either high-dose vitamin D3 (4000 IU) or standard-dose (400 IU) vitamin D3. Body composition was measured with abdominal computed tomography at enrollment (baseline) and after cycle 8 of chemotherapy (16 weeks). As compared with standard-dose vitamin D3, high-dose vitamin D3 did not significantly change body weight [−0.7 kg; (95% CI: −3.5, 2.0)], body mass index [−0.2 kg/m2; (95% CI: −1.2, 0.7)], muscle area [−1.7 cm2; (95% CI: −9.6, 6.3)], muscle attenuation [−0.4 HU; (95% CI: −4.2, 3.2)], visceral adipose tissue area [−7.5 cm2; (95% CI: −24.5, 9.6)], or subcutaneous adipose tissue area [−8.3 cm2; (95% CI: −35.5, 18.9)] over the first 8 cycles of chemotherapy. Among patients with advanced or metastatic colorectal cancer, the addition of high-dose vitamin D3, vs standard-dose vitamin D3, to standard chemotherapy did not result in any changes in body composition

Molecular Heterogeneity and Response to Neoadjuvant Human Epidermal Growth Factor Receptor 2 Targeting in CALGB 40601, a Randomized Phase III Trial of Paclitaxel Plus Trastuzumab With or Without Lapatinib

PURPOSE: Dual human epidermal growth factor receptor 2 (HER2) targeting can increase pathologic complete response rates (pCRs) to neoadjuvant therapy and improve progression-free survival in metastatic disease. CALGB 40601 examined the impact of dual HER2 blockade consisting of trastuzumab and lapatinib added to paclitaxel, considering tumor and microenvironment molecular features. PATIENTS AND METHODS: Patients with stage II to III HER2-positive breast cancer underwent tumor biopsy followed by random assignment to paclitaxel plus trastuzumab alone (TH) or with the addition of lapatinib (THL) for 16 weeks before surgery. An investigational arm of paclitaxel plus lapatinib (TL) was closed early. The primary end point was pCR in the breast; correlative end points focused on molecular features identified by gene expression–based assays. RESULTS: Among 305 randomly assigned patients (THL, n = 118; TH, n = 120; TL, n = 67), the pCR rate was 56% (95% CI, 47% to 65%) with THL and 46% (95% CI, 37% to 55%) with TH (P = .13), with no effect of dual therapy in the hormone receptor–positive subset but a significant increase in pCR with dual therapy in those with hormone receptor–negative disease (P = .01). The tumors were molecularly heterogeneous by gene expression analysis using mRNA sequencing (mRNAseq). pCR rates significantly differed by intrinsic subtype (HER2 enriched, 70%; luminal A, 34%; luminal B, 36%; P < .001). In multivariable analysis treatment arm, intrinsic subtype, HER2 amplicon gene expression, p53 mutation signature, and immune cell signatures were independently associated with pCR. Post-treatment residual disease was largely luminal A (69%). CONCLUSION: pCR to dual HER2-targeted therapy was not significantly higher than single HER2 targeting. Tissue analysis demonstrated a high degree of intertumoral heterogeneity with respect to both tumor genomics and tumor microenvironment that significantly affected pCR rates. These factors should be considered when interpreting and designing trials in HER2-positive disease