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OBJECTIVE: To evaluate expression of potential molecular imaging targets epidermal growth factor receptor (EGFR), glycoprotein nonmetastatic melanoma protein B (GPNMB), and vascular endothelial growth factor (VEGF) in lymph nodes (LNs) with or without head and neck squamous cell carcinoma (HNSCC) metastases after (chemo)radiation.STUDY DESIGN: Retrospective study comparing receptor expression in paired lymph nodes after initial treatment.SETTING: A tertiary referral hospital.SUBJECTS AND METHODS: Salvage neck dissection specimens of 40 patients treated with (chemo)radiation were selected. LNs that contained viable tumor, reactive changes after initial treatment, and normal LNs were analyzed using immunohistochemically determined H-scores and by calculating sensitivity and specificity rates and positive/negative predictive values (PPVs/NPVs).RESULTS: EGFR expression was found in 86% and GPNMB expression in 100% of the LNs with viable tumor. VEGF expression was present in all lymph node types. For EGFR, the sensitivity rate was 86%, and specificity rate was 81%. For GPNMB, these were 100% and 75%, respectively. PPV of EGFR was 61.8% and NPV was 98.2%. These were 56.4% and 100% for GPNMB, respectively.CONCLUSION: In residual or recurrent HNSCC lymph node metastases, both EGFR and GPNMB show tumor-specific expression in immunohistochemistry, which may prove useful in future molecular imaging in salvage neck dissections. Immunohistochemically detected VEGF expression indicates that this target is not feasible for imaging purposes in salvage surgery. Therefore, GPNMB could be a new potential imaging target showing comparable results to EGFR in immunohistochemistry.

Objective: To evaluate expression of the potential molecular imaging targets glycoprotein nonmetastatic melanoma protein B (GPNMB) and vascular endothelial growth factor (VEGF) in comparison to classical epidermal growth factor receptor (EGFR) in previously untreated head and neck cancer primary tumors and corresponding lymph node metastases, and in lymph node metastases after initial (chemo)radiotherapy. Methods: Primary tumors and lymph node metastases of 38 patients who underwent primary resection of head and neck squamous cell carcinoma (HNSCC) were selected. In addition, lymph node metastases from salvage surgery after (chemo)radiotherapy from 22 patients with HNSCC were selected. Immunohistochemical staining for EGFR, VEGF and GPNMB was performed, after which protein expression was scored using H-scores (percentage of positive tumor cells multiplied by staining intensity ranging from 0 to 2). Primary tumors and lymph node metastases with an H-score ≥5 were considered positive, after which sensitivity rates were calculated. Groups were compared using the Mann-Whitney U test for non-parametric data with post-hoc Bonferroni corrections. Results: In untreated primary HNSCC the sensitivity was 86.8% for EGFR (median H-score 60), 92.1% for VEGF (median 60), and 100% for GPNMB (median 100). In previously untreated lymph node metastases the sensitivity was 81.6% for EGFR (median 30), 86.8% for VEGF (median 65), and 100% for GPNMB (median 118). In lymph node metastases after initial (chemo)radiotherapy, sensitivity was 86.4% for EGFR (median 95) and 100% for GPMB (median 100). VEGF sensitivity could not reliably be evaluated in these lymph nodes due to nonspecific staining in all tissue slides. GPNMB expression was significantly higher compared to EGFR in untreated primary HNSCC (p = .009 and p < .001, respectively) and lymph node metastases (p < .001 for both). Conclusion: GPNMB shows better tumor-specific receptor expression in both sensitivity and H-scores compared to EGFR and VEGF in immunohistochemistry. VEGF performed comparable to EGFR in untreated HNSCC and lymph node metastases. GPNMB could therefore be a new potential imaging target based on these immunohistochemical results. Citation Format: Jeroen E. van Schaik, Bert van der Vegt, Saskia H. Hanemaaijer, Gyorgy B. Halmos, Max J. Witjes, Bernard F.A.M. van der Laan, Rudolf S. Fehrmann, Sjoukje F. Oosting, Boudewijn E. Plaat. Comparison of glycoprotein nonmetastatic melanoma protein b, epidermal growth factor receptor and vascular endothelial growth factor expression in head and neck squamous cell carcinoma, and untreated and residual lymph node metastases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6261.

Background: Chemoradiotherapy (CRT) including three cycles of cisplatin is considered the standard of care for locally advanced head and neck squamous cell carcinoma (LA-HNSCC). However, around one-third of the patients cannot complete cisplatin because of toxicity. Carboplatin plus 5-fluorouracil (carbo-5FU) is another accepted treatment option with a different toxicity profile. We compared tolerability and efficacy of concomitant carbo-5FU and cisplatin. Patients and Methods: We conducted a retrospective analysis of LA-HNSCC patients treated with CRT in two Dutch cancer centers between 2007 and 2016. All patients received intensity-modulated radiotherapy. One center routinely administered carboplatin 300–350 mg/m2 at day 1, 22, and 43 followed by 5FU 600 mg/m2/day for 96 h. The other center used cisplatin 100 mg/m2 at day 1, 22, and 43. The primary endpoint of this study was chemotherapy completion rate. Secondary endpoints included overall survival (OS), disease-free survival (DFS), locoregional control (LRC) and distant metastasis–free interval (DMFS), toxicity, and unplanned admissions. Results: In the carbo-5FU cohort (n = 211), 60.2% of the patients completed chemotherapy vs. 76.7% (p < 0.001) of the patients in the cisplatin cohort (n = 223). Univariate analysis showed a higher risk of death in the carbo-5FU cohort [hazard ratio (HR) 1.53, 95% CI, 1.09–2.14, p = 0.01] with a 3-year OS of 65.4 vs. 76.5% for cisplatin. OS was independently associated with T and N stage and p16 status, but not with chemotherapy regimen (HR 1.08, 95% CI, 0.76–1.55, p = 0.65). Three-year DFS was 70.0% for carbo-5FU vs. 78.6% for cisplatin (HR 1.37, 95% CI, 0.93–2.01, p = 0.05). A similar outcome was observed for both LRC (HR 1.27, 95% CI, 0.74–2.09, p = 0.4) and DMFS (HR 1.08, 95% CI 0.62–1.90, p = 0.77). The risk of discontinuation for chemotherapy-associated toxicity was higher in the carbo-5FU cohort than in the cisplatin cohort (relative risk = 1.69). Conclusion: LA-HNSCC patients treated with concomitant carbo-5FU completed chemotherapy less frequently than patients treated with cisplatin. Treatment regimen was not an independent prognostic factor for OS.