The association of Bcl-xL and p53 expression with survival outcomes in oropharyngeal cancer

Challenges and Considerations in Diagnosing and Managing p16+-Related Oropharyngeal Squamous Cell Carcinoma (OPSCC) with Neck Metastasis: Implications of p16 Positivity, Tobacco Exposure, and De-Escalation Strategies

BACKGROUND

The incidence of patients showing neck metastasis and no obvious primary tumor at the initial diagnostic evaluation or neck cancer of unknown primary (NCUP) is rising. It is estimated that a relevant part of these tumors arises in the tonsillar crypts or base of the tongue and are p16+-related. However, today, the detection rate of the primary tumor is suboptimal. Identifying the primary tumor and its biomolecular characterization is essential since it influences the treatment administered, possibly reducing radiation fields and providing de-escalation to primary surgical management. However, p16 IHC (immunohistochemistry) might not be sufficient to diagnose HPV-related OPSCC. The other subset of patients discussed are the HPV-positive patients who have a history of tobacco exposure and/or p53 mutations. Possible factors that could negatively influence the outcomes of these patients are investigated and discussed below. So, this paper aims to analyze the diagnostic, bio-molecular, clinico-radiological, morphological, prognostic and therapeutical aspects of p16-positive OPSCC, highlighting the possible bias that can occur during the diagnostic and prognostic process.

METHODS

A narrative review was conducted to investigate the biases in the diagnostic and therapeutic process of two groups of patients: those who are p16-positive but HPV-negative patients, and those who are p16-positive and HPV-positive with exposure to traditional risk factors and/or p53 mutations. The keywords used for the literature research included the following: NCUP, OPSCC, p16IHC, HPV testing, p16 positive HPV negative OPSCC, p16 positive HPV positive OPSCC, tonsillectomy, tobacco exposure, p53 mutations, cystic neck metastasis, extranodal extension (ENE), radiotherapy, de-escalation and neck neck dissection.

RESULTS

HPV-positive OPSCC has specific clinico-radiological features. Bilateral tonsillectomy should be considered for the identification of the primary tumor. P16 IHC alone is not sufficient for diagnosing HPV-related OPSCC; additional detection methods are required. The role of tobacco exposure and p53 mutations should be investigated especially in cases of HPV-positive tumors. Extranodal extension (ENE) must be taken into consideration in the prognostic staging of HPV-positive tumors. Surgical primary treatment involving neck dissection (ND) and bilateral tonsillectomy followed by adjuvant radiation may represent the most appropriate approach for N3 cases. Diagnosis, prognosis and therapeutical implications must be addressed considering clinical, biomolecular and morphological aspects. At least today, the numerous biases that are still present influencing the diagnostic and prognostic process do not permit considering de-escalation protocols.

CONCLUSIONS

A precise and accurate diagnosis is required in order to adequately stage and manage p16+ OPSCC, particularly with neck metastasis. The role of tobacco exposure and/or p53 mutations must be considered not only in p16+ OPSCC but especially in HPV-positive OPSCC. Until a more accurate diagnosis is possible, ENE should be considered even in p16+HPV+ OPSCC. Primary surgery with unilateral ND and bilateral tonsillectomy might be the treatment of choice given the numerous diagnostic and prognostic pitfalls. Therefore, it is inappropriate and risky to propose de-escalation protocols in routine clinical practice due to the risk of undertreatment.

Evaluation of BH3 mimetics as a combination therapy with irradiation in head and neck squamous cell carcinoma

INTRODUCTION

Head and neck squamous cell carcinoma (HNSCC) is a common cancer with a five-year survival rate around 60%, indicating a need for new treatments. BH3 mimetics are small molecules that inhibit anti-apoptotic Bcl-2 family proteins, resulting in apoptosis induction.

METHODS

We performed a high-throughput screen using a Myogel matrix to identify the synergy between irradiation and the novel BH3 mimetics A-1155463, A-1331852, and navitoclax in 12 HNSCC cell lines, normal (NOF) and cancer-associated fibroblasts (CAF), and dysplastic keratinocytes (ODA). Next, we examined synergy in an apoptosis assay, followed by a clonogenic assay and a Myogel spheroid on selected HNSCC cell lines. Finally, we applied zebrafish larvae xenograft to validate the effects of navitoclax and A-1331852.

RESULTS

All three BH3 mimetics exhibited a strong synergy with irradiation in eight HNSCC cell lines and ODAs, but not in NOFs and CAFs. A-1155463 and A-1331852 induced apoptosis and reduced proliferation, and together with irradiation, significantly increased apoptosis and arrested proliferation. A-1331852 and navitoclax significantly decreased the clonogenicity compared with the control, and combination treatment led to a decreased clonogenicity compared with monotherapy or irradiation. However, unlike navitoclax or A-1155463, only A-1331852 significantly reduced cancer cell invasion. Furthermore, in spheroid and zebrafish, irradiation appeared ineffective and failed to significantly increase the drug effect. In the zebrafish, A-1331852 and navitoclax significantly reduced the tumor area and metastasis.

CONCLUSIONS

Our findings encourage the further preclinical investigation of BH3 mimetics, particularly A-1331852, as a single agent or combined with irradiation as a treatment for HNSCC.

Mitochondrial Dynamics of Bcl-2 Family Proteins during 17-β-Estradiol-Induced Apoptosis Correlate with the Malignancy of Endometrial Cancer Cells

Excessive fat intake leads to an increase in cholesterol. Overexposure to estrogen derived from cholesterol is known to contribute to the malignancy of endometrial adenocarcinomas. However, it is not well understood the relationship between the exposure to estrogen and the malignancy of endometrial adenocarcinomas. We investigated how estrogen affected the malignancy of endometrial cancer cells, specifically HEC1 cells (a moderately differentiated adenocarcinoma) and HEC50B cells (a poorly differentiated adenocarcinoma). Cell viability was decreased by exogenous 17-β-estradiol (E2) in a concentration-dependent manner. E2 disturbed the mitochondrial membrane potentials by changing the localization of the B-cell lymphoma 2 (Bcl-2) family protein; however, there were significant differences in the localization of Bcl-2 family proteins between HEC1 and HEC50B cells. In HEC1 cells, E2 increased the expression of B-cell lymphoma-extra large (Bcl-XL) and the Bcl-2-associated X protein (Bax) and decreased Bcl-2 and Bcl-2-associated death promoter (Bad) expression on the outer mitochondrial membrane. Conversely, E2 increased the expression of Bad and Bax, and it decreased Bcl-2 and Bcl-XL expressions on the outer mitochondrial membrane in HEC50B cells. The disturbance of the mitochondrial membrane potential led to the release of cytochrome c from the mitochondria to the cytosolic space followed by activating caspase-9. After that, caspase-3 was activated and induced apoptosis. These results suggested that the localization of the Bcl-2 family protein observed under E2-induced apoptosis is related to the malignancy of endometrial cancer cells. We hope that the dynamics of Bcl-2 family proteins such as Bcl-XL and Bad will be used to diagnose malignant endometrial adenocarcinomas.

Association of human papillomavirus related squamous cell carcinomas of the oropharynx and cervix

BACKGROUND

Human Papillomavirus (HPV) infection is well established in oropharyngeal squamous cell carcinoma (OPSCC) and cervical cancer (CC). However, the association between both HPV related cancers remains unclear. The purpose of this study was to investigate the association between HPV related cancers of the oropharynx and cervix.

METHODS

A provincial cancer registry was used to retrospectively identify all patients diagnosed with OPSCC from 1997-2015. The standardized incidence ratio (SIR) of CC history in women with p16+/-OPSCC was measured.

RESULTS

From 372 women with OPSCC included, the SIR of CC was significantly higher across all ages compared to the general population in Alberta, Canada (p < 0.0001).

CONCLUSIONS

Women with HPV/p16+ OPSCC have a significantly higher risk of CC compared to the general population.