PD-L1, PARP1, and MMRs as potential therapeutic biomarkers for neuroendocrine cervical cancer

Poly(ADP-ribose) polymerase1 (PARP1) and PARP inhibitors: New frontiers in cervical cancer

Cervical cancer affects more than half a million women and treatment options for advanced disease and recurrence is limited. Poly (ADP-ribose) polymerase1 (PARP1) is a critical nuclear protein regulating several components and functions of cellular machinery, including cancer. PARP1 expression and activity plays a crucial dynamics in the tumor microenvironment. PARP inhibitors are being considered as a viable option for treating BRCA deficient ovarian and breast cancer patients. However, the role of PARP1 in cervical cancer tumorigenesis is less known. The aim of the present review is to provide a comprehensive insight about the role of PARP1 in cervical cancer pathogenesis in context to PARP1 expression as a molecular marker for identifying cancer and in predicting treatment response and prognosis. PARP1 expression is found to be elevated in cervical cancer tissues in comparison to that in the normal surrounding tissues. The cellular proteins linked with PARP1 have been described along with the association of SNPs in PARP1 gene with cervical cancer. Promising results of PARP inhibitors with immunotherapy and clinical trials with cisplatin have also been discussed. This review provides an up-to-date description of PARP1 expression, its role in cervical cancer pathogenesis and reported clinical trials of PARP inhibitors in adjuvant therapy.

Efficacy of PD-1/PD-L1 blockade immunotherapy in recurrent/metastatic high-grade neuroendocrine carcinoma of the cervix: A retrospective study

Although high-grade neuroendocrine carcinoma of the cervix (HGNECC) accounts for less than 1 % of all cervical cancers, it exhibits marked aggressiveness and resistance to radiation and chemotherapy. We retrospectively investigated the efficacy of immunotherapy for recurrent/metastatic HGNECC in a real-world setting. From September 2016 to December 2022, a total of 29 patients with HGNECC accepted PD-1/PD-L1 inhibitors; of these, six cases (20.7 %) were PD-L1 positive (combined positive score ≥1). According to their primary treatment, the patients were assigned to either a surgery group (n = 14) or a non-surgery group (n = 15). In the surgery group, four patients received anti-PD-1 therapy immediately after surgery, while six, two, one, and one patients started immunotherapy after the first, second, third, and forth recurrence, respectively. In the non-surgery group, seven patients started immunotherapy as part of their primary treatment, while the other four, two, and two patients received anti-PD-1 drugs as the second, third, and forth lines of treatment, respectively. The seven-patient group showed longer progression-free survival after immunotherapy (PFSi) and overall survival than those of their counterparts (P = 0.085 and 0.08, respectively), while this benefit was not observed in other subgroups. No significant correlation was observed between PD-L1 and PFSi expression. Interestingly, one patient with a high tumor mutation burden (TMB-H) had a long PFSi of 26 months and experienced no recurrence until the last follow-up. Based on these findings, we propose that PD-1/PD-L1 inhibitors may prolong the survival of patients with HGNECC who start immunotherapy as the first-line of treatment. This indicates that early immunotherapy may be a better choice for this challenging malignancy. Moreover, the predictive role of TMB-H in immunotherapeutic outcomes requires further investigation.

Aversatile MOF as an electrochemical/fluorescence/colorimetric signal probe for the tri-modal detection of MMP-9 secretion in the extracellular matrix to identify the efficacy of chemotherapeutic drugs

BACKGROUND

MMP-9 plays a crucial role in regulating the degradation of proteins within the extracellular matrix (ECM). This process closely correlates with the occurrence, development, invasion, and metastasis of various tumors, each exhibiting diverse levels of MMP-9 expression. However, the accuracy of detection results using the single-mode method is compromised due to the coexistence of multiple biologically active substances in the ECM.

RESULTS

Therefore, in this study, a tri-modal detection system is proposed to obtain more accurate information by cross-verifying the results. Herein, we developed a tri-modal assay using the ZIF-8@Au NPs@S QDs composite as a multifunctional signal probe, decorated with DNA for the specific capture of MMP9. Notably, the probe demonstrated high conductivity, fluorescence response and mimicked enzyme catalytic activity. The capture segments of hybrid DNA specifically bind to MMP9 in the presence of MMP9, causing the signal probe to effortlessly detach the sensor interface onto the sample solution. Consequently, the sensor current performance is weakened, with the colorimetric and fluorescent signals becoming stronger with increasing MMP9 concentration. Notably, the detection range of the tri-modal sensor platform spans over 10 orders of magnitude, verifying notable observations of MMP-9 secretion in four tumor cell lines with chemotherapeutic drugs. Furthermore, the reliability of the detection results can be enhanced by employing pairwise comparative analysis.

SIGNIFICANCE

This paper presents an effective strategy for detecting MMP9, which can be utilized for both the assessment of MMP-9 in cell lines and for analyzing the activity and mechanisms involved in various tumors.

Expression of Programmed Death Ligand 1 [PD-L1] and Mismatch Repair Status in Squamous Cell Carcinomas of Cervix

Background and Objectives

To assess mismatch repair (MMR) status and programmed death-ligand 1 (PD-L1) expression in squamous cell carcinomas of the cervix and their association with clinicopathologic parameters.

Material and Methods

Expression of PD-L1 and MMR status (MSH2, MSH6, MLH1, and PMS2) was assessed on 50 cases of SCCs of the cervix by immunohistochemistry.

Results

80% of tumor cells and 84% of tumor-infiltrating lymphocytes showed PD-L1 expression. 80% of cases had a combined positive score (CPS) of > 1, whereas 20% had a CPS of < 1. 94% of cases showed pMMR proteins, while 6% showed dMMR. 94% of the SCCs were HPV associated, and 6% were HPV-independent. All HPV-independent SCCs of the cervix showed PD-L1 expression, and all HPV-associated SCCs showed MMR deficiency. Between PD-L1 expression in the tumor and the grade of the tumor, a statistically significant association was noted (p = 0.022). All MMR-deficient SCCs were HPV-independent.

Conclusion

This research highlighted the HPV association in cervical SCCs in the Indian population. Most of the cervical SCCs were HPV-associated. Furthermore, most of the HPV-associated SCCs were MMR stable. This study found no significant association between MMR status and PD-L1 expression in cervical SCCs.

Neuroendocrine cervical cancer: Have we made any steps forward in its management?

INTRODUCTION

Neuroendocrine tumors (NEC) were first described by Albores-Saavedra in 1972 and these tumors account for only 0.9% to 1.5% of all invasive cervical cancers.1,2 The most common type is small cell neuroendocrine carcinoma (SCNEC) of the cervix, which accounts for 80% of cases.2 The poor prognosis despite advances in treatment remains still a huge problem, so the aim of our review is to cover all current therapeutic options.

METHOD

We searched for all available interventional studies, reviews, case reports and meta-analyses published from 1995 to 2023.

RESULTS

In 2017 Castle et al.9 published a systematic review and meta-analysis and concluded that SCNC and large cell neuroendocrine carcinoma (LCNC) are, in most cases, caused by HPV, primarily HPV18 and HPV16. Comparative genomics data suggest that cervical NEC may be genetically more similar to common cervical cancer subtypes than to extra-cervical SCNEC of the lung and bladder.13 Surgery is recommended as the primary treatment in early stages of disease, with radical hysterectomy and nodal assessment followed by adjuvant pelvic radiotherapy and/or chemotherapy. However, simple hysterectomy may be adequate when followed by adjuvant radiotherapy with concurrent cisplatin and etoposide as additional chemotherapy.15 Considering that pathologic and clinical behavior is similar to small cell lung cancer, patients usually receive platinum and etoposide as part of their primary therapy.16 The recurrent disease remains a major clinical problem, because there is no standard treatment modality for these patients, and individualized therapy is recommeded.

CONCLUSION

Current therapeutic modalities are mainly based on experience in the treatment of SCNEC of the lung. Certainly, a multidisciplinary approach is very important inorder to design a personalized management plan.

Expression patterns of mismatch repair proteins in cervical cancer uncover independent prognostic value of MSH-2

OBJECTIVE

Although early-detected cervical cancer is associated with good survival, the prognosis for late-stage disease is poor and treatment options are sparse. Mismatch repair deficiency (MMR-D) has surfaced as a predictor of prognosis and response to immune checkpoint inhibitor(s) in several cancer types, but its value in cervical cancer remains unclear. This study aimed to define the prevalence of MMR-D in cervical cancer and assess the prognostic value of MMR protein expression.

METHODS

Expression of the MMR proteins MLH-1, PMS-2, MSH-2, and MSH-6 was investigated by immunohistochemical staining in a prospectively collected cervical cancer cohort (n=508) with corresponding clinicopathological and follow-up data. Sections were scored as either loss or intact expression to define MMR-D, and by a staining index, based on staining intensity and area, evaluating the prognostic potential. RNA and whole exome sequencing data were available for 72 and 75 of the patients and were used for gene set enrichment and mutational analyses, respectively.

RESULTS

Five (1%) tumors were MMR-deficient, three of which were of neuroendocrine histology. MMR status did not predict survival (HR 1.93, p=0.17). MSH-2 low (n=48) was associated with poor survival (HR 1.94, p=0.02), also when adjusting for tumor stage, tumor type, and patient age (HR 2.06, p=0.013). MSH-2 low tumors had higher tumor mutational burden (p=0.003) and higher frequency of (frameshift) mutations in the double-strand break repair gene RAD50 (p<0.01).

CONCLUSION

MMR-D is rare in cervical cancer, yet low MSH-2 expression is an independent predictor of poor survival.

Prognostic model for survival in patients with neuroendocrine carcinomas of the cervix: SEER database analysis and a single-center retrospective study

OBJECTIVE

Neuroendocrine carcinoma of the cervix (NECC) is extremely rare in clinical practice. This study aimed to methodologically analyze the clinicopathological factors associated with NECC patients and to develop a validated survival prediction model.

METHODS

A total of 535 patients diagnosed with NECC between 2004 and 2016 were identified from the Surveillance, Epidemiology and End Results (SEER) database, while 122 patients diagnosed with NECC at Yunnan Cancer Hospital (YCH) from 2006 to 2019 were also recruited. Patients from the SEER database were divided into a training cohort (n = 376) and a validation cohort (n = 159) in a 7:3 ratio for the construction and internal validation of the nomogram. External validation was performed in a cohort at YCH. The Kaplan-Meier method was used for survival analysis, the Log-rank method test was used for univariate analysis of prognostic influences, and the Cox regression model was used for multivariate analysis.

RESULTS

The 3-year and 5-year overall survival (OS) rates for patients with NECC in SEER were 43.6% and 39.7%, respectively. In the training cohort, multivariate analysis showed independent prognostic factors for NECC patients including race, tumor size, distant metastasis, stage, and chemotherapy (p<0.05). For extended application in other cohorts, a nomogram including four factors without race was subsequently created. The consistency index (C-index) of the nomogram predicting survival was 0.736, which was well-validated in the validation cohorts (0.746 for the internal validation cohort and 0.765 for the external validation cohort). In both the training and validation cohorts, the 3-year survival rates predicted by the nomogram were comparable to the actual ones. We then succeeded in dividing patients with NECC into high- and low-risk groups concerning OS using the nomogram we developed. Besides, univariate analysis showed that chemotherapy ≥4 cycles may improve the OS of patients at YCH with NECC.

CONCLUSION

We successfully constructed a nomogram that precisely predicts the OS for patients with NECC based on the SEER database and a large single-center retrospective cohort. The visualized and practical model can distinguish high-risk patients for recurrence and death who may benefit from clinical trials of boost therapy effectively. We also found that patients who received more than 4 cycles of chemotherapy acquired survival benefits than those who received less than 4 cycles.

Extrapulmonary Neuroendocrine Carcinomas: Current Management and Future Perspectives

Neuroendocrine carcinomas (NECs) are poorly differentiated and highly aggressive epithelial neuroendocrine neoplasms. The most common primary site is the lung, but they may arise in every organ. Approximately 37% of extrapulmonary NECs (EP-NECs) occur in the gastroenteropancreatic (GEP) tract, followed by the genitourinary (GU) system and gynecological tract. As a result of their rarity, there is scant evidence to guide treatment recommendations, and a multidisciplinary approach is essential for the management of such patients. Platinum-based chemotherapy currently represents the standard of care for EP-NECs of any site, mirroring the management of small-cell lung cancer (SCLC), but further approaches are still under investigation. Indeed, ongoing trials evaluating targeted therapies, immune checkpoint inhibitors (ICIs), and radionuclide therapy could provide potentially breakthrough therapeutic options. Given the relative dearth of evidence-based literature on these orphan diseases, the aim of this review is to provide an overview of the pathology and current treatment options, as well as to shed light on the most pressing unmet needs in the field.

Expression of neuroendocrine markers predicts increased survival in triple-negative breast cancer patients

Background

The significance of neuroendocrine (NE) markers in triple-negative breast cancer (TNBC) patients has not been investigated. This study aims to clarify the incidence and prognostic significance of NE marker expression in TNBC, determine its association with other clinicopathological parameters, and further explore the pathological features and potential treatment options for TNBC patients expressing NE markers.

Methods

Clinicopathological data were collected from 396 TNBC patients undergoing radical breast cancer surgery at Peking Union Medical College Hospital from January 2002 to December 2014, with a final follow-up in July 2019. Immunohistochemistry (IHC) staining was performed for NE markers including chromogranin A (CgA) and synaptophysin (Syn). For TNBC patients with positive NE marker expression, IHC staining was then performed for alpha-thalassemia/mental retardation X-linked (ATRX), O(6)-methylguanine-methyltransferase (MGMT), somatostatin receptor 2 (SSTR2), and programmed death receptor-ligand 1 (PD-L1). The chi-square or Fisher exact test was used to evaluate the correlations between NE marker expression and other parameters. Survival curves were plotted using the Kaplan-Meier (K-M) method to assess the prognostic significance of NE markers in TNBC.

Results

NE marker-positive staining was observed in 7.6% (30/396) of all TNBC cases. Only 0.5% (2/396) cases had ≥ 90% neoplastic cells expressing NE markers. Positive NE marker expression was associated with negative basal-like marker expression. K-M survival analysis showed that the NE marker-positive TNBC patients had higher disease-free survival (DFS) rates than the NE marker-negative patients at the same stage. Among the 30 NE marker-positive TNBC cases, 13.3% and 26.7% showed negative IHC staining for ATRX and MGMT, respectively, while 13.3% had a 3+ score for SSTR2 IHC staining. For PD-L1 IHC staining, 13.3% of the 30 TNBC cases were higher than 10 scores in Combined Positive Score (CPS), and 10.0% were higher than 10% in Tumor Cell Proportion Score (TPS).

Conclusion

There was a small proportion of TNBC patients expressing NE markers. TNBC patients with positive NE marker expression had a better prognosis than the negative group at the same stage. TNBC cases with positive NE marker expression may potentially benefit from immunotherapy or somatostatin analogue treatment.

Advances in Research, Diagnosis, and Treatment of Neuroendocrine Cervical Carcinoma: A Review

Neuroendocrine neoplasms (NENs) were classified separately in the 5th edition (2020) of the World Health Organization (WHO) classification of female genital malignancies. Cervical neuroendocrine carcinoma (NEC) is distinguished by its low incidence, high invasiveness, early local dissemination, and distant metastases. The purpose of this review is to outline the achievements in pathology, diagnostics, gene sequencing, and multi-modality treatment of cervical NEC.

Incorporation of immunotherapy into the treatment of metastatic neuroendocrine carcinoma of the cervix: A case report

•Ideal treatment for advanced neuroendocrine carcinoma of the cervix (NECC) remains unclear.•A patient with metastatic NECC experienced a durable complete response to multi-modal therapy that included atezolizumab.•Atezolizumab may improve response rates and overall survival when incorporated into therapy for NECC.

PD-L1 expression and prognosis in definitive radiotherapy patients with neuroendocrine cervical carcinoma

Background

Neuroendocrine carcinoma of the cervix (NECC) is more prone to lymphatic infiltration, lymph node involvement, local recurrence, and distant metastasis. Using concurrent chemoradiotherapy (CCRT) with or without adjuvant chemotherapy as the standard treatment for locally advanced NECCs and CCRT for patients with early lesions confined to the cervix. However, the prognosis of NECC patients treated with definitive radiotherapy (RT) is unknown. Immune checkpoint inhibitors are a promising therapeutic strategy for locally advanced cervical cancer. Some reports suggest that the expression of PD-L1 in solid tumors correlates with prognosis.

Aim

This study investigates prognostic factors for survival in patients with neuroendocrine cervical carcinoma (NECC) treated with definitive RT and the relationship between PD-L1 expression and prognosis in these patients.

Methods

This retrospective study included 66 patients with histologically confirmed NECC who received RT with or without chemotherapy. From January 2015 to December 2020, patients received routine extended-field irradiation (EFI), and PD-L1 expression was assessed by immunohistochemistry. The most commonly used chemotherapy agents were etoposide-platinum and paclitaxel-platinum.

Results

PD-L1 expression was positive in 17 of 45 (37.8%) patients. There were 52 cases of pure NECC and 14 cases of mixed carcinoma. Sixty stage IB-III patients received definitive RT. The 3- and 5-year progression-free survival (PFS) was 39.8% and 34.1%, and 3- and 5-year overall survival (OS) was 48.0% and 40.2%, respectively. There was no significant difference in 3 and 5-year PFS and 3 and 5-year OS between patients with pure and mixed carcinoma. Positive PD-L1 expression was associated with higher 3-year PFS in patients with mixed histology. Univariate analysis showed that lymph node metastasis (LNM) and the International Federation of Gynecology and Obstetrics stages predicted 3- and 5-year PFS in patients who received definitive RT. The median OS in patients receiving less than four cycles and at least four cycles of chemotherapy (CT) was 26.0 and 44.0 months, respectively (P = 0.038); moreover, 3- and 5-year PFS was 34.1% and 25.7% in the former and 46.4% and 40.4% in the latter. There were no significant differences in OS and PFS between pelvic irradiation and prophylactic EFI in patients treated with definitive RT. There were no significant differences in para-aortic failure rate after concurrent chemoradiotherapy between patients who underwent pelvic irradiation or prophylactic EFI (P = 0.147).

Conclusion

In patients with mixed NECC, positive PD-L1 expression is correlated with higher 3-year PFS. Chemoradiotherapy was effective for NECCs. The LNM and stage predicted PFS. Four or more cycles of chemotherapy improve prognosis. Prophylactic EFI did not significantly improve PFS and OS.

Relevance for Patients

This study is relevant to patients as it confirms that chemoradiotherapy is effective for both early and locally advanced NECC and that four or more cycles of chemotherapy improved prognosis. The regimen should be carefully evaluated to ensure that patients receive the most effective radiation therapy for the prophylactic of para-aortic LNM. Potential risk factors for the recurrence of radical radiotherapy should be fully understood to minimize these risks. This study observed that PD-L1 expression positive in patients with mixed NECC types is correlated with higher 3-year PFS.

Recent Advances in Cervical Cancer Management: A Review on Novel Prognostic Factors in Primary and Recurrent Tumors

BACKGROUND

Several pathological parameters, including tumor size, depth of stromal invasion, lympho-vascular space invasion and lymph node status, have been proposed as prognostic predictors in cervical cancer. However, given the high mortality and recurrence rate of cervical cancer, novel parameters that are able to provide additional prognostic information are needed in order to allow a better prognostic stratification of cervical cancer patients.

METHODS

A search was conducted on PubMed to identify relevant literature data regarding prognostic factors in cervical cancer. The key words "cervical cancer", "prognostic factors", "pathology", and "outcome" were used.

RESULTS

The novel pathological grading system based on tumor budding and cell nest size appeared the most relevant prognostic factor in primary neoplasms. Moreover, other potentially useful prognostic factors were tumor size, depth of stromal invasion, lympho-vascular space invasion, perineural invasion, tumor-free distance and tumor-infiltrating lymphocytes. Prognostic factors related to advanced-stage cervical cancer, including lymph-nodes status, endometrial and cervical involvement as well as distant metastases, were also taken into consideration.

CONCLUSIONS

According to our findings, tumor budding and cell nest size grading system, depth of stromal invasion, lympho-vascular space invasion, perineural invasion, tumor-free distance and tumor-infiltrating lymphocytes appeared the most relevant factors included in the pathology report.

Positive clinical outcomes following therapy with programmed cell death protein 1/programmed cell death ligand 1 inhibitors in neuroendocrine carcinoma of the cervix

Neuroendocrine carcinoma of the cervix (NECC) is a highly aggressive and rare gynecological malignancy with a poor prognosis. Despite aggressive local and systemic treatments, there are high rates of locoregional recurrence and distant metastases. Therefore, more potent treatments are required to manage NECC. In recent years, emerging immune checkpoint inhibitors, such as programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) inhibitors, have been used in treating various solid tumors and provide a new direction for immune-targeted therapy for NECC. In this review, we summarize the biomarkers useful for the evaluation of the therapy with PD-1/PD-L1 inhibitors in patients with NECC and the clinical applications and prospects of monotherapy with PD-1/PD-L1 inhibitors and combinations with other therapies in patients with NECC. In some individual case reports, therapeutic strategies with PD-1/PD-L1 inhibitors showed good efficacy. Further studies are needed to confirm the possibility of using PD-1/PD-L1 inhibitors as a standard treatment strategy in NECC.

Small Cell (Neuroendocrine) Carcinoma of the Cervix: An Analysis for 19 Cases and Literature Review

Cervical SCNEC is a rare and highly malignant invasive tumor. The incidence is low, at less than 5% of all cervical cancers. Moreover, most patients with small cell carcinoma are interrelated with high risk HPV (more familiar HPV 18). Compared to squamous cell carcinoma or adenocarcinoma, patients of cevical SCNEC are more prone to lymph node invasion early, so the clinical manifestation is usually local or distant metastasis. We summarized the clinical features of 19 patients with cervical small cell carcinoma in the Second Affiliated Hospital of Dalian Medical University from 2012 to 2021, and retrospectively analyzed data from 1576 patients in 20 related studies and more than 50 pieces of literature in recent years by searching PubMed, Google schalor, Cochrane Library, Clinicalkey, and other databases. The collected patient data included age, clinical manifestation, TCT, HPV detection, the size and morphology of the tumor, local invasion depth, stage, lymph node status, initial treatment method, tumor-free survival, and so on. The positive rates of CGA, SYN, and CD56 in our cases were high, and NSE was a moderately sensitive index. P16 and Ki67 were the most sensitive, and all patients were positive. We found that multimodal treatment can indeed improve tumor-free survival (DFS), but the prognosis of patients is still very poor. For the early stages, our treatment principles refer to the guidelines of SGO, international gynecological cancer Cooperation (GCIG), and NCCN. We suggest a combination of surgery, radiotherapy, and chemotherapy. However, the general state of advanced patients is poor, whether they can tolerate the operation after neoadjuvant chemotherapy, whether the operation area can remain tumor-free, and whether this treatment will prolong the survival time of patients still need to be further discussed. In order to better prolong the tumor-free survival and prognosis of patients, we need to find gene changes suitable for targeted therapy, so as to complete the clinical application of these treatment methods. Further works are needed to explore more effective therapy for cervical SCNEC.

PD-L1, PARP1, and MMRs as potential therapeutic biomarkers for neuroendocrine cervical cancer

Objective

Neuroendocrine cervical cancer (NECC) is a rare cervical cancer with high aggressivity that causes poor prognosis even in the early stage. Given other neuroendocrine carcinomas and other types of cervical cancer have been proved to have expression of programmed cell death protein 1 ligand 1(PD‐L1) and poly ADP‐ribose polymerase‐1(PARP1), we would measure and analyze these proteins in this invasive cancer. The purpose of this study is to investigate the application value of PD‐1/PD‐L1 and PARP1 inhibitors in NECC.

Methods

The NECC cases in our center with formalin‐fixed paraffin‐embedded tissue blocks were collected, and immunohistochemical (IHC) staining of PD‐L1, PARP1, Mismatch repair proteins (MMRs), and P53 was performed. Chi‐square test was used to analyze associations between various protein expressions. We analyzed the efficacy of immunotherapy in a recent patient with secondary recurrence after two courses of chemotherapy.

Results

After rigorous screening, 20 cases were finally included. Three cases did not undergo surgical treatment because of their advanced stage. Twelve (60%) developed distant metastases or relapsed within five years, and most of them within two years. The positive rate of PD‐L1 and PARP1 were 70% and 75% respectively. Among all the cases, microsatellite instability (MSI) was seen in six cases (30%) and abnormal p53 expression was in 15 patients (75%). PD‐L1 was associated with PARP1 expression in the MSI subgroup. The patient treated with chemotherapy + VEGF inhibitor (VEGFi) + programmed cell death protein 1(PD‐1) inhibitor had an excellent improvement in clinical symptoms, tumor markers, and mass size.

Conclusion

The IHC results of PD‐L1, PARP1, and MMRs suggested that NECC was the target of immunotargeted therapy. Our case confirmed that immune checkpoint therapy was effective in patients with PD‐L1 positive and MMRs loss. Considering the clinical practicability, more cases should be collected, and effective biomarkers still need to be further searched.