Evaluation of ProExC as a prognostic marker in oropharyngeal squamous cell carcinomas

Recent advances in esophageal squamous cell precancerous conditions: A review

Esophageal squamous cell carcinoma (ESCC) is a common cancer in many developing countries in Asia and Africa, with a 5-year survival rate of approximately 20%. Most cases are diagnosed at an advanced age when there is no effective treatment strategy. Esophageal precancerous conditions have a much better prognosis, with a 5-year survival rate of over 90% by endoscopic diagnosis and treatment. Nevertheless, limitations, contraindications, and lymph node metastasis incompetency of endoscopy. Thus, the diagnosis and treatment of esophageal precancerous lesions remain a significant challenge. Biomarker investigations provide opportunities for target detection and therapy. Additionally, drug development is ongoing. Changes in lifestyle habits, such as diet balance, smoking and alcohol cessation, are beneficial for the prognosis of esophageal precancerous lesions. Collectively, multiple and sequential diagnoses and treatments are essential for curing esophageal precancerous lesions and reducing the incidence and mortality of ESCC.

Quantitative assessment of p16 expression in FNA specimens from head and neck squamous cell carcinoma and correlation with HPV status

BACKGROUND

This study investigated p16 by immunohistochemistry (IHC) on cellblocks (CBs) and human papillomavirus (HPV) by polymerase chain reaction (PCR) in fine-needle aspiration (FNA) of head and neck squamous cell carcinoma (HNSCC).

METHODS

Receiver operating characteristic (ROC) curve analysis was used to assess test performance in CBs compared with p16 IHC in 42 surgical specimens from patients with HNSCC and in correlation with HPV by PCR in cytology specimens. The study assessed HPV by PCR in FNA specimens as a substitute for p16 IHC in surgical specimens.

RESULTS

Of 42 cases, 38 CBs showed malignant cells as cohesive clusters of viable cells with or without single tumor cells, whereas 4 specimens were composed exclusively of single tumor cells and degenerated cells. All p16-negative surgical specimens showed an absence of p16 staining in the corresponding CBs (n = 16). In the p16-positive surgical cases (n = 26), corresponding CBs with tumor clusters (n = 23) showed heterogeneous p16 expression ranging from 40% to 100%; however, scoring single cells was challenging and unreliable because of cellular degradation. ROC curve inspection showed the optimal threshold to be at least 40% p16 staining in tumor clusters with 100% sensitivity and specificity. In cases with inadequate CBs, HPV by PCR on needle rinse showed 88% sensitivity and 100% specificity for p16 expression in surgical specimens.

CONCLUSIONS

A cutoff of at least 40% p16 expression in tumor clusters may be appropriate for p16 positivity in cytology CB specimens. A positive HPV finding by PCR on needle rinse can be used as a substitute for p16 expression in surgical specimens.

Surrogate markers for high-risk human papillomavirus infection in oral epithelial dysplasia: A comparison of p16, Ki-67, and ProExC

OBJECTIVE

The aim of this study was to determine the utility of surrogate markers of human papillomavirus (HPV) infection in the diagnosis of HPV-associated oral epithelial dysplasia (OED).

STUDY DESIGN

Twelve cases of oral dysplasia with histologic features of HPV infection were stained with surrogate markers for HPV (p16, Ki-67, and ProExC) on immunohistochemistry. A second group of 12 cases of oral dysplasia without histologic features of HPV infection was used for comparison. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to confirm the presence of high-risk HPV (HR HPV) in p16-positive cases.

RESULTS

All of the surrogate markers showed a statistically significant association with HPV-positive OED (P < .001). The agreement between p16 and HPV positivity was the strongest (κ = 1.00), whereas Ki-67 showed very good association with HPV (κ = 0.83), and ProExC showed good association (κ = 0.75). In each case, the agreement was statistically significant (P < .001). Overall, each of the 3 markers showed good sensitivity; however, ProExC showed the lowest specificity.

CONCLUSIONS

The clinicopathologic features of 12 cases of HPV OED are reported. Diffuse p16 positivity is an accurate and reliable method for predicting HR HPV infection in both high and low grade cases of epithelial dysplasia with histopathologic features of HPV OED. The use of Ki-67 and ProExC did not demonstrate any additional diagnostic benefit in the diagnosis HPV OED.

Human Papillomavirus Testing in Head and Neck Carcinomas: Guideline From the College of American Pathologists

Context Human papillomavirus (HPV) is a major cause of oropharyngeal squamous cell carcinomas, and HPV (and/or surrogate marker p16) status has emerged as a prognostic marker that significantly impacts clinical management. There is no current consensus on when to test oropharyngeal squamous cell carcinomas for HPV/p16 or on which tests to choose. Objective To develop evidence-based recommendations for the testing, application, interpretation, and reporting of HPV and surrogate marker tests in head and neck carcinomas. Design The College of American Pathologists convened a panel of experts in head and neck and molecular pathology, as well as surgical, medical, and radiation oncology, to develop recommendations. A systematic review of the literature was conducted to address 6 key questions. Final recommendations were derived from strength of evidence, open comment period feedback, and expert panel consensus. Results The major recommendations include (1) testing newly diagnosed oropharyngeal squamous cell carcinoma patients for high-risk HPV, either from the primary tumor or from cervical nodal metastases, using p16 immunohistochemistry with a 70% nuclear and cytoplasmic staining cutoff, and (2) not routinely testing nonsquamous oropharyngeal carcinomas or nonoropharyngeal carcinomas for HPV. Pathologists are to report tumors as HPV positive or p16 positive. Guidelines are provided for testing cytologic samples and handling of locoregional and distant recurrence specimens. Conclusions Based on the systematic review and on expert panel consensus, high-risk HPV testing is recommended for all new oropharyngeal squamous cell carcinoma patients, but not routinely recommended for other head and neck carcinomas.

p16 cutoff in head and neck squamous cell carcinoma: correlation between tumor and patient characteristics and outcome

BACKGROUND

p16 has been indicated as a suitable surrogate biomarker of HPV infection. The prognosis of p16-positive oropharynx tumors (OTs) of squamous cell carcinoma (SCC) histology is better than that of p16-negative tumors.

METHODS

We analyzed 209 samples of head and neck SCC to establish a predictive cutoff for p16 and determine the role of p16 positivity in OTs versus non-OTs. We compared the outcomes of tumors harboring any percentage of p16-positive cells (≥1%) with those of p16-negative OTs. We then considered 3 cutoffs (10%, 50% and 70% positive cells) to evaluate the outcome of OTs/non-OTs with similar p16 expression and p16-positive versus p16-negative tumors stratified by patient age.

RESULTS

p16-negative tumors among OTs and non-OTs were 29% and 49%, respectively (p = 0.0054). The cumulative distribution showed that the positive values were located around 2 focus points: 2% and 96%. Subgroup analysis showed that only OTs occurred in young patients (aged &lt;65 years) and that there was a ≥70% gain in survival in cases with p16-positive cells.

CONCLUSIONS

p16 positivity influences outcome only in young patients and OTs (p = 0.048).

Human papillomavirus 16 detected in nasopharyngeal carcinomas in white Americans but not in endemic Southern Chinese patients

BACKGROUND

We evaluated the relationship of human papillomavirus (HPV) and Epstein-Barr virus (EBV) with race in endemic and nonendemic cohorts of patients with nasopharyngeal carcinoma (NPC), and with smoking status in the nonendemic cohort.

METHODS

Tissue microarrays (TMAs) were constructed using samples from 86 patients treated in southern China and 108 patients from Stanford, California. TMAs were stained with p16, HPV in situ hybridization (ISH), and EBV ISH. Polymerase chain reaction (PCR) was used to confirm EBV(-) cases and HPV status in p16(+) cases. Survival data was available for the Stanford cohort only.

RESULTS

No HPV(+) cases were detected in the Chinese cohort. In the Stanford cohort, 5 of 11 EBV(-) cases harbored HPV-16, 10 of 10 occurred in whites, and 8 of 11 were smokers. Patients with EBV(-) NPC also showed a trend toward worse survival.

CONCLUSION

EBV(-) NPC shows an association with the presence of HPV, white race, and smoking. In contrast, EBV(-) NPC shows no association with HPV in the endemic cohort.

Correlation between human papillomavirus and p16 overexpression in oropharyngeal tumours: a systematic review

Background:

A significant proportion of squamous cell carcinomas of the oropharynx (OP-SCC) are related to human papillomavirus (HPV) infection and p16 overexpression. This subgroup proves better prognosis and survival but no evidence exists on the correlation between HPV and p16 overexpression based on diagnostic measures and definition of p16 overexpression. We evaluated means of p16 and HPV diagnostics, and quantified overexpression of p16 in HPV-positive and -negative OP-SCCs by mode of immunohistochemical staining of carcinoma cells.

Methods:

PubMed, Embase, and the Cochrane Library were searched from 1980 until October 2012. We applied the following inclusion criteria: a minimum of 20 cases of site-specific OP-SCCs, and HPV and p16 results present. Studies were categorised into three groups based on their definition of p16 overexpression: verbal definition, nuclear and cytoplasmatic staining between 5 and 69%, and ⩾70% staining.

Results:

We identified 39 studies with available outcome data (n=3926): 22 studies (n=1980) used PCR, 6 studies (n=688) used ISH, and 11 studies (n=1258) used both PCR and ISH for HPV diagnostics. The methods showed similar HPV-positive results. Overall, 52.5% of the cases (n=2062) were HPV positive. As to p16 overexpression, 17 studies (n=1684) used a minimum of 5–69% staining, and 7 studies (n=764) used ⩾70% staining. Fifteen studies (n=1478) referred to a verbal definition. Studies showed high heterogeneity in diagnostics of HPV and definition of p16. The correlation between HPV positivity and p16 overexpression proved best numerically in the group applying ⩾70% staining for p16 overexpression. The group with verbal definitions had a significantly lower false-positive rate, but along with the group applying 5–69% staining showed a worse sensitivity compared with ⩾70% staining.

Conclusions:

There are substantial differences in how studies diagnose HPV and define p16 overexpression. Numerically, p16 staining is better to predict the presence of HPV (i.e. larger sensitivity), when the cutoff is set at ⩾70% of cytoplasmatic and nuclear staining.