Prevalence of Skip Metastases to Cervical Lymph-Nodes in Oral cavity Cancer in Eastern India-an observational study

To determine the prevalence of skip metastases in Oral-squamous-cell-carcinoma (OSCC). This prospective observational study was carried out on 100-cases of biopsy proven OSCC who underwent surgical treatment for the primary tumor along with neck dissection (ND). Data regarding depth of invasion (DOI) by primary tumor, perineural-invasion, lymphovascular-invasion, presence of metastatic-lymph-node (level, size, number and extranodal-extension) were collected from histopathology reports and were analyzed. Out of 100-cases, 73-were-male and 27-were-female. Mean age was 49.5 ± 12.3 years (range 24-4 years). Common subsites of tumor were buccal-mucosa, tongue and lower-alveolus in 40, 37 and 14% respectively. Pathological staging of tumor were stage-I, stage-II, stage-III, stage-IVa and stage-IVb in 22, 14, 25, 22 and 15% cases respectively. Preoperative neck staging was cN0 in 50 necks (47.2%) and cN+ in 56 necks (52.8%). In 100-patients 106-NDs (unilateral-94 and bilateral-6) were performed. Type of NDs were Supraomohyoid, extended-Supraomohyoid and modified radical neck-dissection in 23,07and76 cases respectively. Prevalence of cervical lymph node metastases was 36% (pN + necks). Among 36pN + patients; 25 (69.4%) cases, 20 (55.5%) cases, 9 (25%) cases, 4 (11.1%) cases, 2 (5.5%) cases had metastases to level-I, II, III, IV and V respectively. Skip-metastases was present in four-cases {level-IIb:one-case (2.78%), level-III: two-cases (5.5%) and level-V:one-case (2.78%)}. No-skip-metastasis to level-IV was noticed. All-four-cases of skip-metastases were from advance cases of squamous-cell-carcinoma of tongue with DOI > 5 mm. Skip-metastases to levels IIb, IV and V are uncommon in cases of OSCC. Most of the metastasis in our study was noted to levels I, II and III in a predictable fashion. Thus, extensive ND can be avoided in patients to prevent complications and morbidities associated with the same.