Carlos Vargas

The impact of common and rare EGFR mutations in response to EGFR tyrosine kinase inhibitors and platinum-based chemotherapy in patients with non-small cell lung cancer

OBJECTIVESnIn non-small cell lung cancer (NSCLC), the association between common EGFR mutations (Del EX19/L858R) with EGFR tyrosine kinase inhibitors (EGFR-TKIs) has been well established. However, this has not been investigated for rare EGFR mutations or their impact on treatment response and outcome to EGFR TKIs (primary objective) and chemotherapy (secondary objective).nnnMATERIALS AND METHODSnIn an observational prospective cohort, we analyzed 188 NSCLC patients from Mexico, Colombia and Costa Rica with EGFR mutations. As a first line of treatment, 66.5% received platinum-based chemotherapy. All patients received TKIs in first-line treatment or after progression to chemotherapy. The clinical-pathological characteristics as well as the f of common and rare EGFR mutations associated with treatment response were analyzed.nnnRESULTSnOf all patients, 79.5% had common and 20.5% had rare EGFR mutations. Lepidic and acinar adenocarcinomas were associated with common EGFR mutations (p=0.010). Patients with common EGFR mutations had higher response rates to EGFR-TKIs than those who had rare EGFR mutations (63.8 vs 32.4%, p<0.001). Women had increased progression-free survival (PFS) to EGFR-TKIs than men (16.4 vs 9.5 months, p=0.02). The median PFS and overall survival (OS) were better in patients with common EGFR mutations (15.5 vs 3.9 months, p<0.001; and 37.3 vs 17.4 months, p<0.001) respectively.nnnCONCLUSIONnOur findings suggested that only patients with rare EGFR mutations could receive platinum-based chemotherapy as a first-line treatment, due to their low response rates and short PFS in response to EGFR-TKIs. Consequently, EGFR-TKIs could be reserved as a second- or third-line treatment. In patients with EGFR mutations, women have better PFS to EGFR-TKIs than men, and rare EGFR mutations are more frequent in high grade adenocarcinomas than in low grade tumors.

Dosimetric study of uniform scanning proton therapy planning for prostate cancer patients with a metal hip prosthesis, and comparison with volumetric-modulated arc therapy

The main purposes of this study were to 1) investigate the dosimetric quality of uniform scanning proton therapy planning (USPT) for prostate cancer patients with a metal hip prosthesis, and 2) compare the dosimetric results of USPT with that of volumetric‐modulated arc therapy (VMAT). Proton plans for prostate cancer (four cases) were generated in XiO treatment planning system (TPS). The beam arrangement in each proton plan consisted of three fields (two oblique fields and one lateral or slightly angled field), and the proton beams passing through a metal hip prosthesis was avoided. Dose calculations in proton plans were performed using the pencil beam algorithm. From each proton plan, planning target volume (PTV) coverage value (i.e., relative volume of the PTV receiving the prescription dose of 79.2 CGE) was recorded. The VMAT prostate planning was done using two arcs in the Eclipse TPS utilizing 6 MV X‐rays, and beam entrance through metallic hip prosthesis was avoided. Dose computation in the VMAT plans was done using anisotropic analytical algorithm, and calculated VMAT plans were then normalized such that the PTV coverage in the VMAT plan was the same as in the proton plan of the corresponding case. The dose‐volume histograms of calculated treatment plans were used to evaluate the dosimetric quality of USPT and VMAT. In comparison to the proton plans, on average, the maximum and mean doses to the PTV were higher in the VMAT plans by 1.4% and 0.5%, respectively, whereas the minimum PTV dose was lower in the VMAT plans by 3.4%. The proton plans had lower (or better) average homogeneity index (HI) of 0.03 compared to the one for VMAT (HI = 0.04). The relative rectal volume exposed to radiation was lower in the proton plan, with an average absolute difference ranging from 0.1% to 32.6%. In contrast, using proton planning, the relative bladder volume exposed to radiation was higher at high‐dose region with an average absolute difference ranging from 0.4% to 0.8%, and lower at low‐ and medium‐dose regions with an average absolute difference ranging from 2.7% to 10.1%. The average mean dose to the rectum and bladder was lower in the proton plans by 45.1% and 22.0%, respectively, whereas the mean dose to femoral head was lower in VMAT plans by an average difference of 79.6%. In comparison to the VMAT, the proton planning produced lower equivalent uniform dose (EUD) for the rectum (43.7 CGE vs. 51.4 Gy) and higher EUD for the femoral head (16.7 CGE vs. 9.5 Gy), whereas both the VMAT and proton planning produced comparable EUDs for the prostate tumor (76.2 CGE vs. 76.8 Gy) and bladder (50.3 CGE vs. 51.1 Gy). The results presented in this study show that the combination of lateral and oblique fields in USPT planning could potentially provide dosimetric advantage over the VMAT for prostate cancer involving a metallic hip prosthesis. PACS number: 87.55.D‐, 87.55.ne, 87.55.dk

Exploratory Study of 4D versus 3D Robust Optimization in Intensity Modulated Proton Therapy for Lung Cancer.

PURPOSEnThe purpose of this study was to compare the impact of uncertainties and interplay on 3-dimensional (3D) and 4D robustly optimized intensity modulated proton therapy (IMPT) plans for lung cancer in an exploratory methodology study.nnnMETHODS AND MATERIALSnIMPT plans were created for 11 nonrandomly selected non-small cell lung cancer (NSCLC) cases: 3D robustly optimized plans on average CTs with internal gross tumor volume density overridden to irradiate internal target volume, and 4D robustly optimized plans on 4D computed tomography (CT) to irradiate clinical target volume (CTV). Regular fractionation (66 Gy [relative biological effectiveness; RBE] in 33 fractions) was considered. In 4D optimization, the CTV of individual phases received nonuniform doses to achieve a uniform cumulative dose. The root-mean-square dose-volume histograms (RVH) measured the sensitivity of the dose to uncertainties, and the areas under the RVH curve (AUCs) were used to evaluate plan robustness. Dose evaluation software modeled time-dependent spot delivery to incorporate interplay effect with randomized starting phases of each field per fraction. Dose-volume histogram (DVH) indices comparing CTV coverage, homogeneity, and normal tissue sparing were evaluated using Wilcoxon signed rank test.nnnRESULTSn4D robust optimization plans led to smaller AUC for CTV (14.26 vs 18.61, respectively; P=.001), better CTV coverage (Gy [RBE]) (D95% CTV: 60.6 vs 55.2, respectively; P=.001), and better CTV homogeneity (D5%-D95% CTV: 10.3 vs 17.7, respectively; P=.002) in the face of uncertainties. With interplay effect considered, 4D robust optimization produced plans with better target coverage (D95% CTV: 64.5 vs 63.8, respectively; P=.0068), comparable target homogeneity, and comparable normal tissue protection. The benefits from 4D robust optimization were most obvious for the 2 typical stage III lung cancer patients.nnnCONCLUSIONSnOur exploratory methodology study showed that, compared to 3D robust optimization, 4D robust optimization produced significantly more robust and interplay-effect-resistant plans for targets with comparable dose distributions for normal tissues. A further study with a larger and more realistic patient population is warranted to generalize the conclusions.

Trends in mastectomy and reconstruction for breast cancer; a twelve year experience from a tertiary care center

BACKGROUNDnMany surgical options exist for breast cancer, including breast conserving therapy (BCT), mastectomy with reconstruction (MAST+RECON) or without reconstruction (MAST). Long-term results regarding oncologic outcomes are few and primarily retrospective studies.nnnMETHODSnA retrospective review of a prospectively collected database of patients undergoing breast surgery for breast cancer from 2002 to 2014 was performed. Patients were separated into 3 time periods for analysis: 2002 to 2005, 2006 to 2009, and 2010 to 2014. Recurrence outcomes were compared at 4xa0years between MAST+RECON patients.nnnRESULTSnTwo thousand seventy-six patients were identified: 61.2% underwent BCT, 19.7% had MAST, and 19.1% had MAST+RECON. BCT patients were older and had smaller tumors. MAST+RECON increased in prevalence, whereas BCT decreased. Implant-based reconstruction and conservative mastectomy rates increased over the study period. Four-year local recurrence-free rates were similar in nipple-sparing and skin-sparing mastectomy groups.nnnCONCLUSIONSnBCT usage has decreased, trending toward immediate, nipple-sparing mastectomy, implant-based reconstruction. Surgeons should be aware of trends to optimally offer patients their surgical options.

Proton therapy patterns-of-care and early outcomes for Hodgkin lymphoma: results from the Proton Collaborative Group Registry.

Bradford S. Hoppe, Henry Tsai, Gary Larson, George E. Laramore, Carlos Vargas, Yolanda D. Tseng, Megan Dunn, Lisa McGee, Oren Cahlon and William Hartsell University of Florida Health Proton Therapy Institute, Jacksonville, Florida, USA; Procure Proton Therapy Center, Somerset, New Jersey, USA; Procure Proton Therapy Center, Oklahoma City, Oklahoma, USA; Seattle Cancer Care Alliance Proton Therapy Center, Seattle, Washington, USA; Mayo Clinic, Scottsdale, Arizona, USA; Chicago Proton Center, Warrenville, Illinois, USA; Memorial Sloan-Kettering Cancer Center, New York City, New York, USA

Epithelial-mesenchymal transition, proliferation, and angiogenesis in locally advanced cervical cancer treated with chemoradiotherapy.

We evaluated the association between epithelial–mesenchymal transition (EMT)‐derived markers and expression of proteins associated with cell proliferation and tumor growth, as well as their prognostic roles, in 61 patients (mean age 52 ± 10 years) with locally advanced cervical cancer, all of whom were treated with chemoradiation and intracavitary brachytherapy. We used immunohistochemical analysis to assess the expression of proteins targeted in our investigation. Various statistical analyses were then conducted to assess protein marker associations with survival outcomes. Forty‐six percent of the patients were positive for human papilloma virus. Median progression‐free survival (PFS) was 6.6 months (95% confidence interval [CI]: 4.0–9.1, whereas overall survival (OS) was 30.0 months (95% CI: 11–48). Multivariate analysis demonstrated that vascular endothelial growth factor (VEGF) (P = 0.002), epidermal growth factor receptor (EGFR) (P = 0.001), and TWIST2 (P = 0.001) expression levels, as well as a tumor size <6 cm (P = 0.02), influenced OS. Changes in TWIST2 levels and loss of E‐cadherin expression were correlated with VEGF and EGFR levels; furthermore, patients with high TWIST2 expression had shorter OS (P = 0.0001), as those with loss of E‐cadherin (P = 0.02). OS was even shorter when positive EGFR or VEGF expression was related with EMT markers (positive EGFR + negative E‐cadherin: median 14 months, 95% CI: 3–24; negative EGFR + positive E‐cadherin: median 31 months, 95% CI: 14–NA; P = 0.02.). The presence of EMT markers was associated with proliferative and pro‐angiogenic protein expression and influenced the prognosis of locally advanced cervical cancer.

Image-guided hypofractionated proton beam therapy for low-risk prostate cancer: Analysis of quality of life and toxicity, PCG GU 002.

AIMnThis interim analysis evaluated changes in quality of life (QOL), American Urological Association Symptom Index (AUA), or adverse events (AEs) among prostate cancer patients treated with hypofractionation.nnnBACKGROUNDnResults for hypofractionated prostate cancer with photon therapy are encouraging. No prior trial addresses the role of proton therapy in this clinical setting.nnnMATERIALS AND METHODSnForty-nine patients with low-risk prostate cancer received 38-Gy relative biologic effectiveness in 5 treatments. They received proton therapy at 2 fields a day, magnetic resonance imaging registration, rectal balloon, and fiducial markers for guidance pre-beam. We evaluated AEs, Expanded Prostate Index Composite (EPIC) domains, and AUA at pretreatment and at 3, 6, 12, 18, and 24 months. An AUA change >5 points and QOL change of half a standard deviation (SD) defined clinical significance.nnnRESULTSnMedian follow-up was 18 months; 17 patients reached follow-up of ≥24 months. For urinary function, statistically and clinically significant change was not seen (maximum change, 3). EPIC urinary QOL scores did not show statistically and clinically significant change at any end point (maximum, 0.45 SD). EPIC bowel QOL scores showed small but statistically and clinically significant change at 6, 12, 18, and 24 months (SD range, 0.52-0.62). EPIC sexual scores showed small but statistically and clinically significant change at 24 months (SD, 0.52). No AE grade ≥3 was seen.nnnCONCLUSIONSnPatients treated with hypofractionated proton therapy tolerated treatment well, with excellent QOL scores, persistently low AUA, and no AE grade ≥3.

Pemetrexed/Carboplatin/Bevacizumab followed by Maintenance Pemetrexed/Bevacizumab in Hispanic Patients with Non-Squamous Non-Small Cell Lung Cancer: Outcomes according to Thymidylate Synthase Expression

Objective To evaluate the efficacy and safety of pemetrexed, carboplatin and bevacizumab (PCB) followed by maintenance therapy with pemetrexed and bevacizumab (PB) in chemotherapy-naïve patients with stage IV non-squamous non-small cell lung cancer (NSCLC) through the influence of thymidylate synthase (TS) protein and mRNA expression on several outcomes. The primary endpoints were the overall response rate (ORR), progression-free survival (PFS) and overall survival (OS). Methods A cohort of 144 patients were administered pemetrexed (500 mg/m2), carboplatin (AUC, 5.0 mg/ml/min) and bevacizumab (7.5 mg/kg) intravenously every three weeks for up to four cycles. Maintenance PB was administered until disease progression or unacceptable toxicity. Results One hundred forty-four Colombian patients with a median follow-up of 13.8 months and a median number of 6 maintenance cycles (range, 1–32) were assessed. The ORR among the patients was 66% (95% CI, 47% to 79%). The median PFS and (OS) rates were 7.9 months (95% CI, 5.9–10.0 months) and 21.4 months (95% CI, 18.3 to 24.4 months), respectively. We documented grade 3/4 hematologic toxicities, including anemia (14%), neutropenia (8%), and thrombocytopenia (16%). The identified grade 3/4 non-hematologic toxicities were proteinuria (2%), venous thrombosis (4%), fatigue (11%), infection (6%), nephrotoxicity (2%), and sensory neuropathy (4%). No grade >3 hemorrhagic events or hypertension cases were reported. OS was significantly higher in patients with the lowest TS mRNA levels [median, 29.6 months (95% CI, 26.2–32.9)] compared with those in patients with higher levels [median, 9.3 months (95% CI, 6.6–12.0); p = 0.0001]. TS expression (mRNA levels or protein expression) did not influence the treatment response. Conclusion Overall, PCB followed by maintenance pemetrexed and bevacizumab was effective and tolerable in Hispanic patients with non-squamous NSCLC. This regimen was associated with acceptable toxicity and prolonged OS, particularly in patients with low TS expression. We found a role for Ki67 and TS expression as prognostic factors.

BIM deletion polymorphisms in Hispanic patients with non-small cell lung cancer carriers of EGFR mutations

Background Germline alterations in the proapoptotic protein Bcl-2-like 11 (BIM) can have a crucial role in diverse tumors. To determine the clinical utility of detecting BIM deletion polymorphisms (par4226 bp/ par363 bp) in EGFR positive non-small-cell lung cancer (NSCLC) we examined the outcomes of patients with and without BIM alterations. Results BIM deletion was present in 14 patients (15.7%). There were no significant differences between patients with and without BIM-del in clinical characteristics or EGFR mutation type; however, those with BIM-del had a worse overall response rate (ORR) to erlotinib (42.9% vs. 73.3% in patients without BIM-del; p=0.024) as well as a significantly shorter progression-free survival (PFS) (10.8 BIM-del+ vs. 21.7 months for patients without BIM-del; p=0.029) and overall survival (OS) (15.5 BIM-del+ vs. 34.0 months for patients without BIM-del; p=0.035). Multivariate Cox regression analysis showed that BIM-del+ was an independent indicator of shorter PFS (HR 3.0; 95%CI 1.2-7.6; p=0.01) and OS (HR 3.4; 95%CI 1.4-8.3; p=0.006). Methods We studied 89 NSCLC Hispanic patients with EGFR mutation who were treated with erlotinib between January 2009 and November 2014. BIM deletion polymorphisms (BIM-del) was analyzed by PCR in formalin-fixed paraffin-embedded (FFPE) tissues of tumor biopsies. We retrospectively analyzed clinical characteristics, response rate, toxicity, and outcomes among patients with and without BIM-del. Conclusions The incidence of BIM-del found in Hispanic patients is similar to that previously described in Asia. This alteration is associated with a poor clinical response to erlotinib and represents an independent prognostic factor for patients who had NSCLC with an EGFR mutation.

Low Levels of Acute Toxicity Associated With Proton Therapy for Low-Grade Glioma: A Proton Collaborative Group Study.

1Willis-Knighton Cancer Center, Shreveport, LA; 2Louisiana State University Health Sciences Center, Shreveport, LA; 3Northwestern Medicine Chicago Proton Center, Warrenville, IL; 4Procure Proton Therapy Center, Oklahoma City, OK; 5University of Washington Medical Center and SCCA Proton Therapy Center, SeaYle, WA; 6Mayo Clinic Arizona, ScoYsdale, AZ 7University of Texas MD Anderson Cancer Center, Houston, Texas; 8MassachuseYs General Hospital, Boston, MA; 9Miami Cancer Instute, Bapst Health South Florida, Miami, FL