PIK3CA mutations may predict response to PI3K/AKT/mTOR inhibitors in patients with advanced cancers, but the relevance of mutation subtype has not been investigated. Patients with diverse cancers referred to the Clinical Center for Targeted Therapy were analyzed for PIK3CA and, if possible, KRAS mutations. Patients with PIK3CA mutations were treated, whenever possible, with agents targeting the PI3K/AKT/mTOR pathway. Overall, 105 (10%) of 1,012 patients tested harbored PIK3CA mutations. Sixty-six (median 3 prior therapies) of the 105 PIK3CA-mutant patients (including 16 individuals (of 55 PIK3CA-mutant patients tested) with simultaneous KRAS mutations) were treated on a protocol that included a PI3K/AKT/mTOR pathway inhibitor; 17% (11/66) achieved a partial response (PR). Patients with a PIK3CA H1047R mutation compared to patients with other PIK3CA mutations or patients with wild-type PIK3CA treated on the same protocols had a higher PR rate (6/16, 38% vs. 5/50, 10% vs. 23/174, 13%, respectively; all p ≤ 0.02). None of the 16 patients with co-existing PIK3CA and KRAS mutations in codon 12 or 13 attained a PR (0/16, 0%). Patients treated with combination therapy vs. single-agent therapies had a higher PR rate (11/38, 29% vs. 0/28, 0%; p=0.002). Multivariate analysis showed that H1047R was the only independent factor predicting response (odds ratio (OR) 6.6, 95% CI 1.02–43.0, p = 0.047). Our data suggest that interaction between PIK3CA mutation H1047R vs. other aberrations and response to PI3K/AKT/mTOR axis inhibitors warrants further exploration.

Despite a wealth of preclinical studies, it is unclear whether PIK3CA or PTEN gene aberrations are actionable in the clinical setting. Of 1,656 patients with advanced, refractory cancers tested for PIK3CA or PTEN abnormalities, PIK3CA mutations were found in 9% (146/1,589), and PTEN loss and/or mutation in 13% (149/1,157). In multicovariable analysis, treatment with a PI3K/AKT/mTOR inhibitor was the only independent factor predicting response to therapy in individuals harboring a PIK3CA or PTEN aberration. The rate of stable disease (SD) ≥6 months/partial response reached 45% in a subgroup of individuals with H1047R PIK3CA mutations. Aberrations in the PI3K/AKT/mTOR pathway are common and potentially actionable in patients with diverse advanced cancers. This work provides further important clinical validation for continued and accelerated use of biomarker-driven trials incorporating rational drug combinations.

Although the oral cavity is easily accessible to inspection, patients with oral cancer most often present at a late stage, leading to high morbidity and mortality. Autofluorescence imaging has emerged as a promising technology to aid clinicians in screening for oral neoplasia and as an aid to resection, but current approaches rely on subjective interpretation. We present a new method to objectively delineate neoplastic oral mucosa using autofluorescence imaging.Autofluorescence images were obtained from 56 patients with oral lesions and 11 normal volunteers. From these images, 276 measurements from 159 unique regions of interest (ROI) sites corresponding to normal and confirmed neoplastic areas were identified. Data from ROIs in the first 46 subjects were used to develop a simple classification algorithm based on the ratio of red-to-green fluorescence; performance of this algorithm was then validated using data from the ROIs in the last 21 subjects. This algorithm was applied to patient images to create visual disease probability maps across the field of view. Histologic sections of resected tissue were used to validate the disease probability maps.The best discrimination between neoplastic and nonneoplastic areas was obtained at 405 nm excitation; normal tissue could be discriminated from dysplasia and invasive cancer with a 95.9% sensitivity and 96.2% specificity in the training set, and with a 100% sensitivity and 91.4% specificity in the validation set. Disease probability maps qualitatively agreed with both clinical impression and histology. Autofluorescence imaging coupled with objective image analysis provided a sensitive and noninvasive tool for the detection of oral neoplasia.

BackgroundThe purpose of this study was to evaluate the ability of high-resolution microendoscopy to image and quantify changes in cellular and architectural features seen in early oral neoplasia in vivo.MethodsA high-resolution microendoscope (HRME) was used to image intact, resected oral squamous carcinoma specimens. HRME images were reviewed and classified as non-neoplastic or neoplastic by expert clinicians. An algorithm based on quantitative morphologic features was also used to classify each image. Results were compared to the histopathologic diagnosis.ResultsHRME images were obtained from 141 sites in resected specimens from 13 patients. Subjective image interpretation yielded sensitivity and specificity of 85% to 90% and 80% to 85%, respectively, whereas the objective classification algorithm achieved sensitivity and specificity of 81% and 77%, respectively.ConclusionHigh-resolution microendoscopy of intact oral mucosa can provide images with sufficient detail to classify oral lesions by both subjective image interpretation and objective image analysis. © 2011 Wiley Periodicals, Inc. Head Neck, 2011

PIK3CA mutations are frequently diagnosed in diverse cancers and may predict response to PI3K/AKT/mTOR inhibitors. It remains unclear whether they are associated with other characteristics. We analyzed characteristics and outcome of 90 consecutive patients with diverse advanced tumors and PIK3CA mutations and 180 wild-type PIK3CA controls matched by tumor type, gender, and age referred to the Clinical Center for Targeted Therapy. PIK3CA and MAPK mutations (KRAS, NRAS, and BRAF) were analyzed using polymerase chain reaction-based DNA sequencing. The most frequent PIK3CA mutations were E545K (31/90, 34%), E542K (16/90, 18%) in exon 9, and H1047R (20/90, 22%) in exon 20. PIK3CA mutations compared to wild-type PIK3CA were associated with simultaneous KRAS (p=0.047) and MAPK mutations (p=0.03), but only MAPK mutations were confirmed as having an independent association in multivariate analysis. Rates of lung, bone, liver and brain metastases were similar in PIK3CA-mutant and wild-type patients. Patients with PIK3CA mutations treated on trials with PI3K/AKT/mTOR inhibitors had a higher partial/complete response (PR/CR) rate than wild-type PIK3CA patients treated with their best phase I therapy (10/56, 18% vs. 12/152, 8%; p=0.045), but not a prolonged progression-free survival. Patients with H1047R PIK3CA mutations had a higher PR/CR rate with PI3K/AKT/mTOR inhibitors compared to wild-type PIK3CA patients treated with their best phase I therapy (6/16, 38% vs. 12/152, 8%; p=0.003). In conclusion, PIK3CA mutations in diverse cancers were not associated with clinical characteristics, but were correlated with MAPK mutations. PIK3CA mutations, especially, H1047R, were associated with attaining a PR/CR to PI3K/AKT/mTOR pathway inhibitors.