Long-term results of elective mucosal irradiation for head and neck cancer of unknown primary in Chinese population: The EMICUP study

Head and Neck Cancer of Unknown Primary: A Multicenter Retrospective Cohort study in Northern Thailand, an Endemic Nasopharyngeal Cancer Area

OBJECTIVE

This study aimed to evaluate the characteristics and oncological outcomes of head and neck carcinoma of unknown primary (HNCUP) patients in an endemic nasopharyngeal cancer (NPC) area.

METHODS

One hundred and forty-four HNCUP patients curatively treated between January 1995 and December 2022 from 5 centers were retrospectively recruited onto the study to analyze the clinicopathological characteristics and oncological outcomes and compare them with historical data. A multivariate Cox proportional hazards model analysis was performed to evaluate factors affecting survival outcomes. A propensity-matched pair analysis of the patients with positive and negative EBV-encoded small RNA (EBER) staining was applied to compare the characteristics and outcomes between the two groups.

RESULTS

The median follow-up time was 45 months. Most patients (88.2%) received total mucosal irradiation (TMI). Primary tumor emergence (PTE) was detected in 6 patients (4.2%) who did not have TMI. The 5-year overall survival (OS), disease-free survival, and locoregional recurrence-free survival were 51.3%, 64.9%, and 72.7%, respectively. Extranodal extension and N3 compared with the N1 stage were the significant independent predictors for OS (HR 2.90, 95% CI 1.12-7.51, p = 0.028 and HR 3.66, 95%CI 1.23-11.89, p = 0.031, respectively). The matched-pair analysis demonstrated comparable all survival outcomes between the EBER-positive and -negative groups. All patients in the matched pair analysis received TMI, and no PTE was detected.

CONCLUSION

Our survival outcomes were comparable to previous studies with a low rate of PTE. The matched pair analysis of EBER-positive and -negative groups revealed similar oncological outcomes and no primary tumor emergence when total mucosal irradiation was administered.

Systematic review of the CUP trials characteristics and perspectives for next-generation studies

BACKGROUND

Research on therapeutic strategies for patients with unknown primary cancer (CUP) has been underwhelming. This paper summarized and evaluated the CUP therapeutic research over the previous five years. Based on this evaluation, recommendations for clinical trial designs are made to improve the impact of CUP research on patients.

METHODS

Published and ongoing research were evaluated. PubMed was searched from January 1, 2015, to November 1, 2021. The start date of 2015 was chosen to identify research published after ESMO issued new diagnostic and therapeutic guidelines. The US National Library of Medicine indexed ongoing clinical trials.

FINDINGS

Of the 244 CUP studies indexed in PubMed, 11.9% were prospective studies, and 4.9% were clinical trials. The review protocol deemed 65 publications eligible for full-text review. Eleven studies evaluating therapeutic regimens were retained. The two prospective studies and non-randomized trials showed promising outcomes for site-specific treatments. Randomized clinical trials were less promising; however, the trials had recruitment challenges resulting in biased accrual and the inability to keep pace with advancing diagnostics and therapeutics. Most of the 35 ongoing studies were phase II single-arm trials assessing immune checkpoint inhibitors (ICI) or site-specific therapies among CUP patients with suspected favorable prognoses.

CONCLUSION

Our evaluation suggests two prospective clinical trial designs that addressed recent study design and recruitment challenges. A visionary approach uses a multi-arm, multistage randomized trial to address rapid advancements in diagnosis and therapy. A pragmatic approach utilizes a single-arm trial with historical controls to overcome comparison group and recruitment challenges.

Sparing the Larynx and Hypopharynx With Radiation Therapy for Squamous Cell Carcinoma of Unknown Primary Site and Predominant Adenopathy in Level IIA

PURPOSE

There is controversy about the need to target the mucosa of the larynx and hypopharynx during radiation therapy (RT) for squamous cell carcinoma of an unknown primary site (SCCA-UP). By 1997, the policy in our department was to target only the oropharynx and nasopharynx in patients with SCCA-UP metastatic to the level II cervical nodes. The purpose of this study was to report the rate of cancer recurrence in the larynx or hypopharynx using an approach that excluded these areas from the RT target volumes.

METHODS AND MATERIALS

The inclusion criteria for this study were RT in our department for SCCA-UP between January 1, 1997, and December 31, 2019; no history of surgery that could disrupt the cervical lymphatics; predominant adenopathy in level IIA; and neck stage N1-2c. We excluded N3 because the incidental dose to the larynx and hypopharynx is usually high in patients with a >6-cm nodal conglomerate.

RESULTS

The study population was comprised of 50 patients with a median follow-up after RT of 7.1 years. No patient developed recurrent cancer in a mucosal site (0/50), 2% (1/50) developed a neck recurrence in a high-dose area with synchronous distant metastases, and 2% (1/50) developed distant metastases with no evidence of local or regional recurrence.

CONCLUSIONS

When delivering RT for SCCA-UP metastatic predominantly to level IIA, it is not necessary to target the mucosa of the larynx or hypopharynx. The extent to which the incidental RT dose to these areas contributes to cancer control is not evaluated in this study.

Carcinoma of Unknown Primary and the 8th Edition TNM Classification for Head and Neck Cancer

OBJECTIVE

In the 8th Edition TNM Classification for Head and Neck Cancer, the classification for carcinoma of unknown primary (CUP) changed in addition to oropharyngeal carcinomas. The current classification considers extranodal extension (ENE), determination of p16 (surrogate marker for human papillomavirus), and detection of Epstein-Barr virus (EBV). The aim of this study was to investigate the influence of the new classification on the prognosis of p16-positive and p16-negative CUP and the impact of EBV proof.

METHODS

Clinical and pathological data from patients with CUP of the head and neck between 2009 and 2018 were evaluated. The 7th (UICC7) and 8th (UICC8) edition of the Union for International Cancer Control staging system were applied and compared.

RESULTS

There were 97 patients treated, 26.8% women and 73.2% men. The average age at initial diagnosis was 64.6 years. Of which, 58.8% had a documented history of smoking, 37.1% were positive for p16, 4.1% were positive for EBV, and 66% had ENE. Most of the patients were at stage III/IVa (78.4% according to UICC7). According to UICC8, p16+ patients were mainly at stage I (86.1%), and p16- at stage IVb (56.1%). P16 status (P = .002), ENE (P = .001), nodal category (TNM7, P < .001), UICC stage (TNM7, P < .001) and UICC stage (TNM8, P < .001) had a significant impact on survival in the univariate analysis. The 8th TNM classification resulted in a downstaging of p16-positive CUP syndromes and an upstaging of p16-negative syndromes.

CONCLUSION

The 8th TNM classification shows the lower UICC stage in p16-positive CUP syndromes. The prognostic significance for survival has improved from the 7th to the 8th TNM classification. LEVEL OF EVIDENCE USING THE 2011 OCEBM: Level 3. Laryngoscope, 131:E2534-E2542, 2021.

Long-term results of elective mucosal irradiation for head and neck cancer of unknown primary in Chinese population: The EMICUP study

Objective

Controversy still exists regarding the volume of radiation for head and neck cancer of unknown primary (HNCUP). Theoretically, elective mucosal irradiation (EMI) should achieve a balance between survival and toxicity. This prospective study was conducted to evaluate the long‐term benefit of EMI in Chinese HNCUP patients.

Methods

A phase II, single‐arm trial was performed at two centers in China. HNCUP patients with pathologically confirmed metastatic squamous cell carcinoma or poorly differentiated carcinoma were enrolled. Patients with metastatic lymph nodes limited to level IV and/or the supraclavicular fossa were excluded. The EMI approach was specifically customized to Chinese patients by differentiating HNCUP as putative nasopharyngeal carcinoma (NPC) or non‐putative NPC. The primary endpoint was 3‐year mucosal recurrence‐free survival (MRFS).

Results

A total of 48 patients were enrolled between 02/02/2010 and 08/01/2018; 46 patients were analyzed, including 24 putative NPC and 22 non‐putative NPC patients. No primary recurrence was observed during a median follow‐up period of 70 months, and only 1 patient experienced out of field recurrence in the contralateral neck. The 3‐year MRFS was 90.6% (95%CI: 76.4%‐96.4%). The 5‐year MRFS, regional‐recurrence free survival (RRFS) and overall survival (OS) were 90.6% (95%CI: 76.4%‐96.4%), 86.0% (95%CI: 71.1%‐93.7%), and 90.6% (95%CI: 76.4%‐96.4%), respectively. No grade 4 acute or late toxicities occurred, and the most frequent grade 3 acute toxicity was oral mucositis (45.7%).

Conclusion

To the best of our knowledge, this is the first prospective study to evaluate the long‐term outcomes of EMI in Chinese HNCUP patients. Excellent MRFS and OS rates were observed. Further randomized studies are warranted.