To explore the potential of tumor-specific DNA as a biomarker for head and neck squamous cell carcinomas (HNSCC), we queried DNA from saliva or plasma of 93 HNSCC patients. We searched for somatic mutations or human papillomavirus genes, collectively referred to as tumor DNA. When both plasma and saliva were tested, tumor DNA was detected in 96% of 47 patients. The fractions of patients with detectable tumor DNA in early- and late-stage disease were 100% (n = 10) and 95% (n = 37), respectively. When segregated by site, tumor DNA was detected in 100% (n = 15), 91% (n = 22), 100% (n = 7), and 100% (n = 3) of patients with tumors of the oral cavity, oropharynx, larynx, and hypopharynx, respectively. In saliva, tumor DNA was found in 100% of patients with oral cavity cancers and in 47 to 70% of patients with cancers of the other sites. In plasma, tumor DNA was found in 80% of patients with oral cavity cancers, and in 86 to 100% of patients with cancers of the other sites. Thus, saliva is preferentially enriched for tumor DNA from the oral cavity, whereas plasma is preferentially enriched for tumor DNA from the other sites. Tumor DNA in saliva was found postsurgically in three patients before clinical diagnosis of recurrence, but in none of the five patients without recurrence. Tumor DNA in the saliva and plasma appears to be a potentially valuable biomarker for detection of HNSCC.

Purpose Ipilimumab (Ipi), a monoclonal antibody against cytotoxic T-lymphocyte antigen-4, has been shown to improve survival in patients with metastatic melanoma. In this single-institution study, we investigate the safety and efficacy of stereotactic radiosurgery (SRS) for patients with melanoma brain metastases (BMs) who also received Ipi. Methods From 2005 to 2011, 46 patients with melanoma received Ipi and underwent single fraction SRS for BMs. A total of 113 BMs (91% intact, 9% post-operative) were treated with median dose 21Gy (15-24Gy). Ipi was given at 3mg/kg (54%) or 10mg/kg (46%) for a median of 4 doses (1-21). Adverse events were recorded using CTCAE 3.0. Kaplan-Meier methods were used to estimate survival and Cox regression was used to investigate associations. Results Fifteen patients received SRS during Ipi, 19 received SRS before Ipi, and 12 received SRS after Ipi. Overall survival (OS) was significantly associated with timing of SRS/Ipi (p=0.035) and melanoma-specific graded prognostic assessment (p=0.013). Patients treated with SRS during or before Ipi had better OS and less regional recurrence (RR) than those treated with SRS after Ipi (1-yr OS 65% vs. 56% vs. 40%, p=0.008; 1-yr RR 69% vs. 64% vs. 92%, p=0.003). SRS during Ipi also yielded a trend toward less local recurrence (LR) than SRS before or after Ipi (1-yr LR 0% vs. 13% vs. 11%, p=0.21). On MRI, an increase in BM diameter to >150% was seen in 50% of patients treated during or before Ipi but only 13% of patients treated after Ipi. Grade 3-4 toxicities were seen in 20% of patients. Conclusion Overall, the combination of Ipi and SRS appears to be well tolerated. Concurrent delivery of Ipi and SRS is associated with favorable locoregional control and possibly longer survival. It may also cause a temporary increase in tumor size, possibly due to enhanced immunomodulatory effect.

Head and neck cancer (HNC) broadly includes carcinomas arising from the mucosal epithelia of the head and neck region as well as various cell types of salivary glands and the thyroid. As reflected by the multiple sites and histologies of HNC, the molecular characteristics and clinical outcomes of this disease vary widely. In this Review, we focus on established and emerging biomarkers that are most relevant to nasopharyngeal carcinoma and head and neck squamous-cell carcinoma (HNSCC), which includes primary sites in the oral cavity, oropharynx, hypopharynx and larynx. Applications and limitations of currently established biomarkers are discussed along with examples of successful biomarker development. For emerging biomarkers, preclinical or retrospective data are also described in the context of recently completed comprehensive molecular analyses of HNSCC, which provide a broad genetic landscape and molecular classification beyond histology and clinical characteristics. We will highlight the ongoing effort that will see a shift from prognostic to predictive biomarker development in HNC with the goal of delivering individualized cancer therapy.

Background Human papillomavirus (HPV) tumor status and surgical salvage are associated with improved prognosis for patients with recurrent oropharyngeal squamous cell carcinoma (OPSCC). Current data regarding types of surgery and the impact of surgery for distant metastatic disease are limited. Methods A retrospective analysis of patients with recurrent OPSCC from two institutions between 2000-2012 was performed. P16 immunohistochemistry and/or in situ hybridization, as clinically available, were used to determine HPV tumor status. Clinical characteristics, distribution of recurrence site and treatment modalities were compared by HPV tumor status. Overall survival was examined by Kaplan-Meier and Cox proportional hazards methods. Results The study included 108 patients with 65 locoregional and 43 distant metastatic first recurrences. The majority were HPV-positive (n=80). HPV-positive tumor status was associated with longer time to recurrence (p<0.01). Anatomic site distribution of recurrences did not differ by HPV tumor status. HPV-positive tumor status (adjusted HR [aHR] 0.23 (95%CI 0.09-0.58), p=0.002), longer time to recurrence (≥1 year; aHR 0.36 (0.18-0.74), p=0.006), and surgical salvage (aHR 0.26 (0.12-0.61), p=0.002) were independently associated with overall survival after recurrence. Surgical salvage was independently associated with improved overall survival compared to non-surgical treatment in both locoregional (aHR 0.15 (0.04-0.56), p=0.005) and distant metastatic recurrence (aHR 0.19 (0.05-0.75), p=0.018). Conclusions Surgical salvage is associated with improved overall survival for recurrent locoregional and distant metastatic OPSCC, independent of HPV tumor status. Further prospective data is needed to confirm the role of surgical salvage for distant metastases.

There has been no established qualitative system of interpretation for therapy response assessment using PET/CT for head and neck cancers. The objective of this study was to validate the Hopkins interpretation system to assess therapy response and survival outcome in head and neck squamous cell cancer patients (HNSCC). Methods The study included 214 biopsy-proven HNSCC patients who underwent a posttherapy PET/CT study, between 5 and 24 wk after completion of treatment. The median follow-up was 27 mo. PET/CT studies were interpreted by 3 nuclear medicine physicians, independently. The studies were scored using a qualitative 5-point scale, for the primary tumor, for the right and left neck, and for overall assessment. Scores 1, 2, and 3 were considered negative for tumors, and scores 4 and 5 were considered positive for tumors. The Cohen κ coefficient (κ) was calculated to measure interreader agreement. Overall survival (OS) and progression-free survival (PFS) were analyzed by Kaplan–Meier plots with a Mantel–Cox log-rank test and Gehan Breslow Wilcoxon test for comparisons. Results Of the 214 patients, 175 were men and 39 were women. There was 85.98%, 95.33%, 93.46%, and 87.38% agreement between the readers for overall, left neck, right neck, and primary tumor site response scores, respectively. The corresponding κ coefficients for interreader agreement between readers were, 0.69–0.79, 0.68–0.83, 0.69–0.87, and 0.79–0.86 for overall, left neck, right neck, and primary tumor site response, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of the therapy assessment were 68.1%, 92.2%, 71.1%, 91.1%, and 86.9%, respectively. Cox multivariate regression analysis showed human papillomavirus (HPV) status and PET/CT interpretation were the only factors associated with PFS and OS. Among the HPV-positive patients (n = 123), there was a significant difference in PFS (hazard ratio [HR], 0.14; 95% confidence interval, 0.03–0.57; P = 0.0063) and OS (HR, 0.01; 95% confidence interval, 0.00–0.13; P = 0.0006) between the patients who had a score negative for residual tumor versus positive for residual tumor. A similar significant difference was observed in PFS and OS for all patients. There was also a significant difference in the PFS of patients with PET-avid residual disease in one site versus multiple sites in the neck (HR, 0.23; log-rank P = 0.004). Conclusion The Hopkins 5-point qualitative therapy response interpretation criteria for head and neck PET/CT has substantial interreader agreement and excellent negative predictive value and predicts OS and PFS in patients with HPV-positive HNSCC.

During 1995 through 2012, the proportion of OPSCCs caused by HPV has increased significantly. This increase was not restricted to white men but was a consistent trend for women and men, as well as for white and nonwhite racial groups. Few non-OP HNSCCs were HPV related. P16 positivity was a good surrogate for ISH+ tumor status among OPSCC, but not a good surrogate for non-OP HNSCC.

Alpha-particle emitters have a high linear energy transfer and short range, offering the potential for treating micrometastases while sparing normal tissues. We developed a urea-based, 211 At-labeled small molecule targeting prostate-specific membrane antigen (PSMA) for the treatment of micrometastases due to prostate cancer (PC). Methods: PSMA-targeted (2S)-2-(3-(1-carboxy-5-(4-211 At-astatobenzamido) pentyl)ureido)-pentanedioic acid ( 211 At-6) was synthesized. Cellular uptake and clonogenic survival were tested in PSMA-positive (PSMA1) PC3 PIP and PSMA-negative (PSMA−) PC3 flu human PC cells after 211 At-6 treatment. The antitumor efficacy of 211 At-6 was evaluated in mice bearing PSMA1 PC3 PIP and PSMA-PC3 flu flank xenografts at a 740-kBq dose and in mice bearing PSMA1, luciferase-expressing PC3-ML micrometastases. Biodistribution was determined in mice bearing PSMA1 PC3 PIP and PSMA-PC3 flu flank xenografts. Suborgan distribution was evaluated using α-camera images, and microscale dosimetry was modeled. Longterm toxicity was assessed in mice for 12 mo. Results: 211 At-6 treatment resulted in PSMA-specific cellular uptake and decreased clonogenic survival in PSMA1 PC3 PIP cells and caused significant tumor growth delay in PSMA1 PC3 PIP flank tumors. Significantly improved survival was achieved in the newly developed PSMA1 micrometastatic PC model. Biodistribution showed uptake of 211 At-6 in PSMA1 PC3 PIP tumors and in kidneys. Microscale kidney dosimetry based on α-camera images and a nephron model revealed hot spots in the proximal renal tubules. Long-term toxicity studies confirmed that the dose-limiting toxicity was late radiation nephropathy. Conclusion: PSMA-targeted 211 At-6 α-particle radiotherapy yielded significantly improved survival in mice bearing PC micrometastases after systemic administration. 211 At-6 also showed uptake in renal proximal tubules resulting in late nephrotoxicity, highlighting the importance of long-term toxicity studies and microscale dosimetry.

Auger electron emitters such as 125I have a high linear energy transfer and short range of emission (<10 μm), making them suitable for treating micrometastases while sparing normal tissues. We used a highly specific small molecule targeting the prostate-specific membrane antigen (PSMA) to deliver 125I to prostate cancer cells. Methods The PSMA-targeting Auger emitter 2-[3-[1-carboxy-5-(4-125I-iodo-benzoylamino)-pentyl]-ureido]-pentanedioic acid (125I-DCIBzL) was synthesized. DNA damage (via phosphorylated H2A histone family member X staining) and clonogenic survival were tested in PSMA-positive (PSMA+) PC3 PIP and PSMA-negative (PSMA−) PC3 flu human prostate cancer cells after treatment with 125I-DCIBzL. Subcellular drug distribution was assessed with confocal microscopy using a related fluorescent PSMA-targeting compound YC-36. In vivo antitumor efficacy was tested in nude mice bearing PSMA+ PC3 PIP or PSMA− PC3 flu flank xenografts. Animals were administered (intravenously) 111 MBq (3 mCi) of 125I-DCIBzL, 111 MBq (3 mCi) of 125I-NaI, an equivalent amount of nonradiolabeled DCIBzL, or saline. Results After treatment with 125I-DCIBzL, PSMA+ PC3 PIP cells exhibited increased DNA damage and decreased clonogenic survival when compared with PSMA− PC3 flu cells. Confocal microscopy of YC-36 showed drug distribution in the perinuclear area and plasma membrane. Animals bearing PSMA+ PC3 PIP tumors had significant tumor growth delay after treatment with 125I-DCIBzL, with only 1 mouse reaching 5 times the initial tumor volume by 60 d after treatment, compared with a median time to 5 times volume of less than 15 d for PSMA− PC3 flu tumors and all other treatment groups (P = 0.002 by log-rank test). Conclusion PSMA-targeted radiopharmaceutical therapy with the Auger emitter 125I-DCIBzL yielded highly specific antitumor efficacy in vivo, suggesting promise for treatment of prostate cancer micrometastases.