Neben-Wittich, M.A.

AbstractBackgroundCutaneous squamous cell carcinomas (CSCC) involving the head and neck are common, but initial presentation or recurrence limited to the cranial nerves is rare.MethodsWe conducted a retrospective study of 21 patients with clinical perineural invasion (PNI) from CSCC and no measurable disease by RECIST 1.1. Patients treated with radiotherapy or chemoradiotherapy were included.ResultsThe median time from symptom onset until diagnosis was 13.0 months (2.6–83.1). All patients received radiotherapy. Fourteen received concurrent systemic therapy. The median follow‐up time was 30.5 months (1.1–106.0). Ten patients recurred, with the majority being locoregional. The 2‐year overall survival rate was 85%. The median progression‐free survival (PFS) was 21.5 months with an estimated 2‐year PFS of 44.5% (95%CI: 22.3–66.8).ConclusionsCSCCs with clinical PNI alone are difficult to diagnose and can have a long interval between appearance of symptoms and diagnosis. They can successfully be treated with chemoradiotherapy. However, many patients still suffer from locoregional recurrences.

239 Background: After trastuzumab (T) approval for advanced HER2-positive E/GEJ-AC, HER2 testing has increased in patients (pts) with resectable disease. Neoadjuvant carboplatin/paclitaxel chemoradiation (nCP-CRT) is a common therapy approach. We performed the largest evaluation, to our knowledge, of the prognostic impact of HER2 in E/GEJ-AC pts treated with nCP-CRT. Methods: We retrospectively reviewed medical records of all trimodality-eligible (T2+ or N+) pts with E/GEJ-AC who started nCP-CRT (usually 50.4 Gy) with planned surgery at Mayo Clinic (2014-2019). HER2 was tested using standard criteria for HER2 positivity (ie, immunohistochemistry 3+ or amplification by in situ hybridization). Clinicopathologic data and time to recurrence (TTR), disease free survival (DFS), overall survival (OS), survival after recurrence (SAR), and pathologic complete response (pCR – ie, no residual tumor in primary or nodes) were collected. Kaplan Meier and multivariate Cox analysis were used. Results: Of 161 consecutive eligible pts, HER2 status was available in 107 pts (HER2-positive n=26, HER2-negative n=81) of whom n=82 had surgery and n=19 had pCR. Most tumors were clinical T3 (80%) or N+ (81%), histologic grade 3 of 3 (62%). HER2 positivity was significantly associated with lower grade, but not with age, clinical T or N, or ECOG performance status (PS). A similar proportion of HER2-positive ( vs negative) pts had surgery. Among pts who had surgery, pCR rates were lower in HER2-positive ( vs negative) pts (11% [2/19] vs 27% [17/63]). After a median follow up of 23 mo, DFS and TTR were significantly shorter in HER2 positive ( vs negative) pts, independent of other pretreatment covariables (Table). Yet OS was comparable. Lung recurrence was enriched in HER2 positive ( vs negative) pts. Among pts with recurrence, SAR was longer in HER2-positive vs -negative pts. A total of 53% (10/19) of previously HER2-positive pts received T-based therapy after recurrence, and these pts were the drivers of favorable SAR (median 22 mo in n=10 HER2-positive pts who received T vs 11 mo in n=9 HER2-positive pts who did not receive T vs 11 mo in n=40 HER2-negative pts; P log-rank=.01). Conclusions: HER2 positivity ( vs negativity) is independently associated with shorter TTR and DFS, but more comparable OS. The adverse association of HER2 on tumor response and TTR may have been largely overcome through enhanced survival after recurrence, although OS data are maturing. These data may have implications for the design of endpoints in future curative-intent anti-HER2 trials. [Table: see text]

AbstractBackgroundAggressive dose de‐escalated adjuvant radiation therapy (RT) in patients with human papillomavirus–associated oropharyngeal squamous cell carcinoma (HPV(+)OPSCC).MethodsPatients with HPV(+)OPSCC on a phase II clinical trial of primary surgery and neck dissection followed by dose de‐escalated RT (N = 79) were compared with a cohort of patients who received standard adjuvant therapy (N = 115). Local recurrence‐free, regional recurrence‐free, distant metastases‐free survival, and progression‐free survival (PFS) were assessed.ResultsOf 194 patients, 23 experienced progression at a median of 1.1 years following surgery (interquartile range [IQR] 0.7‐2.0; range 0.3‐5.4); 10 patients in the de‐escalated cohort and 13 patients in the standard cohort. The 3‐year PFS rate for the de‐escalated cohort was 87%, and in the standard cohort was 90% (hazard ratio [HR] 1.18, 95% confidence interval (CI) [0.50‐2.75]).ConclusionPatients with HPV(+)OPSCC who undergo surgical resection and neck dissection and meet criteria for adjuvant therapy can undergo aggressive dose de‐escalation of RT without increasing risk of progression locally, regionally or at distant sites.

We sought to determine the incidence and location of human papillomavirus (HPV)–associated anogenital disease in women with HPV‐positive oropharyngeal squamous cell carcinoma (OPSCC) via a retrospective cohort study with prospective contact to update history at Mayo Clinic in Rochester, Minnesota. Females undergoing treatment for nonmetastatic HPV‐positive OPSCC from 2011 to 2019 were identified. Clinical history and outcomes were abstracted from medical records. Patients without documented anogenital history were contacted, consented, and administered a survey, and external records were requested and reviewed. Seventeen of 46 patients (37.0%) had a history of anogenital HPV‐associated disease, and 16 of 17 (94.1%) required procedures to diagnose or treat HPV lesions. The cervix was the most common site (16/17, 94.1%). Procedures included colposcopy (n = 6), cervical excision (n = 3), cryotherapy (n = 4), and hysterectomy (n = 3). One case of fatal cervical carcinoma was noted, diagnosed 1 year following OPSCC. Three of 17 (17.6%) had HPV‐related vulvovaginal disease, and 1 of 17 had anal disease. Patients with a history of HPV‐positive OPSCC may be at elevated risk for HPV‐associated anogenital disease.

6095 Background: Prognosis for patients (pts) with locally-advanced, HPV-positive oropharynx squamous cell carcinoma (HPV+OPSCC) is significantly better than for pts with HPV-negative head and neck squamous cell carcinoma (HNSCC). Historic survival of pts with metastatic HNSCC is 6-9 months with palliative therapy. However, the prognosis and survival of pts with HPV+OPSCC with distant metastases is not known. Methods: Pts with HPV+OPSCC with distant metastatic disease were identified from databases from the departments of surgery, radiation, and medical oncology. Demographic and clinical data was abstracted from the medical record. All pts had confirmed HPV/p16+ disease. Results: Fifteen pts with metastatic HPV+ OPSCC were identified. The median age was 57 years (range 42-78, 15 male). The median pack-year smoking was 0 (range 0-120). Primary site included 10 tonsil and 5 tongue base. At diagnosis, one pt had stage III and 14 had stage IV disease (IVA: 9, IVB: 2, IVC: 3). T- and N-stage included T1 (1), T2 (10), T3 (3), T4 (1) and N1 (1), N2a (1), N2b (9), N2c (3), N3 (1). Extracapsular extension was seen in 8 pts, absent in 2, and unknown in 5. Seven pts had lymph node (LN) involvement at level IV/V. Initial therapy for locally-advanced disease included surgery followed by adjuvant radiation (RT) in 1 pt and chemoRT in 8, and definitive chemoRT in 3 pts. Three pts were metastatic at initial diagnosis. Of 6 pts with an isolated metastatic site, 3 pts are alive > 2 years from diagnosis of metastasis (median 1.97 years, range 0.49-2.29). Palliative therapy included surgery (3), RT (9), platinum chemo +/- cetuximab (8), cetuximab alone (2) or with a taxane (2). The most common sites of metastasis included bone (6), lung (5), and LNs (5). The 1-year survival rate after diagnosis of metastatic disease was 92%. The median time to diagnosis of metastatic disease after definitive therapy was 0.47 years (95% CI 0.19-1.29); 75% of pts who developed metastatic disease did so within 1 year of definitive therapy. Of note, 2 of the 15 pts developed a secondary immune-mediated malignancy (melanoma and non-HIV associated Kaposi’s sarcoma). Conclusions: The survival of pts with metastatic HPV+OPSCC is significantly better than that of historic controls.

Background: Anaplastic thyroid cancer (ATC) has poor prognosis with median overall survival (OS) of ∼6 months. We previously reported high PD-1/PDL-1 staining in ATC, raising the possibility of the productive application of the immunotherapeutic pembrolizumab. However, having found pembrolizumab to anecdotally have limited single-agent activity in ATC, we sought to alternatively define whether pembrolizumab might synergistically combine with chemoradiotherapy as initial ATC therapy. Methods: An investigator-initiated therapeutic phase 2 trial of pembrolizumab, 200 mg intravenously (IV) every 3 weeks, combined with chemoradiotherapy (docetaxel/doxorubicin, 20 mg/m 2 each IV weekly plus volumetric modulated arc therapy) was initiated as frontline therapy (with or without surgery) in ATC to assess efficacy and toxicities. Six-month OS was selected as the primary endpoint using a Simon's optimal design with interim analysis (targeting accrual of 25 patients; Cohort A: prior resection, Cohort B: no resection). Based on a prior patient cohort-treated similarly, but without pembrolizumab, the design was such that, if 6-month true survival is 75%, the probability of declaring the approach worthy of further pursuit would be 91%. Results: Three patients were enrolled, two with rapidly enlarging unresectable neck masses. Early tumor responses were favorable in all three, and all three satisfactorily completed: intended radiotherapy, preceding and radiotherapy-concurrent pembrolizumab, and concurrent chemoradiotherapy. However, all three patients died <6 months following therapy initiation—one from pulmonary metastases and two from otherwise unexpected fatal pulmonary complications occurring subsequent to chemoradiotherapy completion—prompting study closure. Conclusions: Although initially tolerated and effective in terms of locoregional disease control, disappointing survival outcomes compared with historical controls raise uncertainty that the piloted approach merits further pursuit in ATC.

PURPOSE The purpose of this study was to determine if dose de-escalation from 60 to 66 Gy to 30 to 36 Gy of adjuvant radiotherapy (RT) for selected patients with human papillomavirus–associated oropharyngeal squamous cell carcinoma could maintain historical rates for disease control while reducing toxicity and preserving swallow function and quality of life (QOL). PATIENTS AND METHODS MC1273 was a single-arm phase II trial testing an aggressive course of RT de-escalation after surgery. Eligibility criteria included patients with p16-positive oropharyngeal squamous cell carcinoma, smoking history of 10 pack-years or less, and negative margins. Cohort A (intermediate risk) received 30 Gy delivered in 1.5-Gy fractions twice per day over 2 weeks along with 15 mg/m 2 docetaxel once per week. Cohort B included patients with extranodal extension who received the same treatment plus a simultaneous integrated boost to nodal levels with extranodal extension to 36 Gy in 1.8-Gy fractions twice per day. The primary end point was locoregional tumor control at 2 years. Secondary end points included 2-year progression-free survival, overall survival, toxicity, swallow function, and patient-reported QOL. RESULTS Accrual was from September 2013 to June 2016 (N = 80; cohort A, n = 37; cohort B, n = 43). Median follow-up was 36 months, with a minimum follow-up of 25 months. The 2-year locoregional tumor control rate was 96.2%, with progression-free survival of 91.1% and overall survival of 98.7%. Rates of grade 3 or worse toxicity at pre-RT and 1 and 2 years post-RT were 2.5%, 0%, and 0%. Swallowing function improved slightly between pre-RT and 12 months post-RT, with one patient requiring temporary feeding tube placement. CONCLUSION Aggressive RT de-escalation resulted in locoregional tumor control rates comparable to historical controls, low toxicity, and little decrement in swallowing function or QOL.

6071 Background: Phase III data suggests a benefit of HDC in the adjuvant setting, but the effect of HDC and WC on long term survival and for HPV+ HNSCC is unknown. Methods: Data from a published retrospective study (Geiger Oral Onc 2013) of HDC vs WC in resected HNSCC was updated. Overall survival (OS) and recurrence-free survival (RFS) was assessed by Kaplan-Meier method for all pts and by HPV status. Multivariate analyses were performed to assess impact of HPV status, smoking, age, HDC vs WC, and cumulative cisplatin dose ( < 200mg/m2 vs ≥200 mg/m2). Results: 51 patients (pts) received HDC and 53 WC. Median follow-up was 8.7 yrs (0.8-13.7). For the whole cohort, HDC had significantly improved OS over WC (p = 0.0095; 5- and 10-yr OS 84% and 80% vs 72% and 60%). No OS benefit for HDC was seen in pts with HPV+HNSCC (5- and 10-yr OS 90% and 87% for HDC and 81% and 81% for WC; p = 0.51). For HPV-negative HNSCC, OS had borderline significance with HDC vs WC (5- and 10-yr OS 73% and 68% vs 65% and 44%; p = 0.06). For the whole cohort, there was no difference in 5- and 10-yr RFS (78% and 74% for HDC vs 72% and 62% for WC; p = 0.32). When analyzed by HPV status, there was no difference in RFS with HDC or WC for either HPV+ (p = 0.43) or HPV-negative HNSCC (p = 0.97). On multivariate analyses of OS for all pts, only HPV status was significant (p = 0.0011; HR 0.27, CI 0.12-0.62). For HPV+ HNSCC, there was no significant predictor of OS. For non-HPV HNSCC, the benefit of HDC approached significance with a decreased risk of death (HR 0.38; p = 0.07). For all pts, those who received ≥200mg/m2 had significantly improved OS (5-yr 90% vs 72% and 10-yr 86% vs 61%; p = 0.004). By HPV status, cumulative dose had no significant effect on OS. Conclusions: OS is better with HDC and with cumulative dose > 200 mg/m2 in unselected patients. The benefit of cisplatin is likely higher for non-HPV HNSCC. A difference in OS with no difference in RFS suggests non cancer-related causes of death in the WC cohort. Ability to receive HDC could be a surrogate marker of comorbidity. [Table: see text]

147 Background: Lymphopenia during radiation therapy (RT) has been associated with worse oncologic outcomes in a number of malignancies, including esophageal cancer (EC). No studies to date have investigated specific dosimetric parameters associated with this lymphopenia in EC. We performed an analysis of RT dose to multiple organs at risk (OARs) to investigate associations with grade 4 lymphopenia (G4L). Methods: Consecutive EC patients receiving curative intent chemoradiotherapy +/- surgery between July of 2015 and December of 2017 were included. Lymphocyte nadir was defined as the lowest lymphocyte count during RT. G4L was defined as absolute lymphocyte count <200/mm3. Dose to OARs including aorta, body, bone marrow, heart, liver, lung, and spleen were calculated. Univariate logistic regression analyses were performed for each OAR at the 1, 5, 10, 15, 20, 30, 35, 40, and 50 Gy levels with volume receiving dose ‘x’(VxGy) analyzed as a continuous variable per 10% increase. Clinical tumor volume (CTV) and RT modality (photon vs. proton) as well clinical factors including sex, stage (I/II vs. III/IV), age (per 10 year increase), and BMI (per 5 unit increase) were also analyzed. Results: One hundred forty-four pts were identified for inclusion. Seventy-nine pts received photon RT and 65 proton RT. Chemotherapy was weekly carbotaxol (99%). G4L at nadir was 40% overall (56% photon, 22% proton). By organ, body V1-V30Gy (OR 1.45-8.18, p<0.01), heart V1-V30Gy (OR 1.24-1.49, p<0.01), liver V1-V35Gy (OR 1.23-2.75, p<0.01), lung V1-V30Gy (OR 1.26-5.73 p<0.01), and spleen V1-V40Gy (OR 1.26-1.49 p<0.01) were highly associated with G4L whereas dose to aorta and bone marrow were not. Advanced stage (OR, 3.92 p<0.01), photon vs. proton (OR 4.58 p<0.01), and CTV (per 100 cc’s (OR=1.21, p<0.01)) were also associated with G4L. Sex, age, and BMI were not associated with G4L. Conclusions: Low to intermediate dose volumes to OARs including body, spleen, liver, lungs, and heart were associated with G4L. These findings provide rational for the differences seen in rates of G4L for photon versus proton RT.