High expression of podoplanin in squamous cell carcinoma of the tongue occurs predominantly in patients ≤40 years but does not correlate with tumour spread

Abstract

More than 30% of patients with squamous cell carcinoma (SCC) of the mobile tongue have clinically undetectable lymph node metastasis. Tumour cells can spread as single cells or collectively. A protein known to play a role in both processes is podoplanin, which is expressed in endothelial cells not only in lymph vessels but also in some aggressive tumours with high invasive and metastatic potential. Here we studied samples from 129 patients with primary SCC of the tongue for expression of podoplanin using immunohistochemistry. mRNA levels were analysed in another 27 cases of tongue SCC with adjacent clinically tumour‐free tongue tissue and 14 tongue samples from healthy donors. Higher levels of podoplanin were seen in tumours compared to both normal tongue and clinically normal tongue in the tumour vicinity. No association was found between levels of podoplanin, presence of lymph node metastases or other clinical factors. Patients aged 40 or less were more likely to express high levels of podoplanin protein compared to older patients (p = 0.027). We conclude that levels of podoplanin in primary tongue SCCs are not associated with lymph node metastases. However, tongue SCCs arising in young patients (≤40 years of age) are more likely to express high levels of podoplanin than tongue SCCs that arise in the more elderly. The data suggest that podoplanin has a distinctive role in young patients, who are known to have a poor prognosis: these patients may, therefore, benefit from podoplanin inhibitory therapies.

Patients with high c‐MYC‐expressing squamous cell carcinomas of the tongue show better survival than those with low‐ and medium‐expressing tumours

“…16 The former finding has implications for therapeutic use as there are antibodies available against podoplanin. 17 When looking at the oncoprotein c-MYC, age did not seem to influence its levels in TSCC, whereas, in accordance with previous findings, 12 gender did, with females showing more low-expressing and males more high-expressing tumours.…”

“…Apart from showing higher recurrence rate in young patients, we have previously shown specific characteristics for young patients with TSCC such as higher levels of the podoplanin protein and worse prognosis when lacking expression of the p16 tumour suppressor protein . The former finding has implications for therapeutic use as there are antibodies available against podoplanin …”

Molecular basis of oral squamous cell carcinoma in young patients: Is it any different from older patients?

“…Comparative immunohistochemical analyses of different molecular markers involved in various pathways are also available. OSCC from young patients presents higher expression of EGFR, MMP‐9, VEGF‐C, and podoplanin when compared to OSCC of older patients . In contrast, higher expression of PCNA and CYP1B1 was observed in older patients .…”

High podoplanin and low E‐cadherin levels correlate with better prognosis in adenoid cystic carcinoma

“…Looking at expression of podoplanin, there were significantly more ACCs expressing high levels compared with both MECs and PACs. In a previous study of 129 squamous cell carcinomas of the oral tongue, we saw a tendency for higher levels in young patients (Sgaramella et al, 2016). Even if the present group of 18 ACCs is not comparable, there were more high-expressing tumours in patients up to 60 years where four out of five (80%) had a QS of 12-18 compared with the old age group (61 and above), where five out of 13 tumours (38%) were high expressing.…”