**9. Conclusions**

technique. For instance, application of the free radial forearm flap into patients with soft tissue defects of tongue, the floor of mouth or retromolar trigone apparently performs an excellent result. In addition to the purpose of covering the soft tissue, the free flap is also a reliable method for recovering the bone defects, such as the

mandibulectomy. Other combined microvascular flanges could be considered as radial forearm osteocutaneous flap, iliac crest and scapula free flaps. What's more, a few studies have demonstrated the effectiveness and safety of microsurgery [34]. The potency to recover major defects after surgery has contributed to improving the oncologic outcomes in patients with locally advanced stage due to increased ability to complete resection [35]. Pedicled myocutaneous flaps such as the pectoralis major, latissimus dorsi or trapezius flaps may also be a promising alternative when there is no reconstructive surgeon or the patient's condition is

Postoperative adjuvant therapy is indicated to patients with high risks of the local, regional recurrence, including pT3,4 primary tumors, pN2,3 lymph node metastases, level IV or V lymph node metastases, positive margins, lymphovascular invasion, perineural invasion and extracapsular spread. Indeed, external beam radiation is the traditional adjuvant treatment, with doses of 60–70 Gy often providing positive control. Two clinical trials have shown that adjuvant radiotherapy with cisplatin significantly improves the control rates along with survival time compared to the single adjuvant radiation therapy in those who have invasive head and neck cancer with extracapsular spread [36, 37]. But for all that concomitant radiotherapy has more severe side effects, so it should be carried out in the large

The clinical stage is the key predictor of survival. The Surveillance, Epidemiology and End Results (SEER) Cancer Statistics reveal that a 5-year survival for locally advanced oral cavity cancer of 54.7%, in contrast to 82.5% for early-stage cancer patients treated from 1975 to 2007 [38]. Lymph node metastasis is the single most important prognostic factor for oncologic outcome in oral cancer [39]. Besides, the number and size of positive lymph nodes, the presence of extranodal extension higher histologic grade, the presence of perineural invasion and increasing size have

Oral cancer has a high risk of local, regional recurrence and development of a secondary primary cancer, but the recurrent rate due to distant metastases is relatively low. The contingency of the second cancer is about 4–7% annually [43]. A comprehensive clinical examination and high vigilance are the cornerstones of the early diagnosis. That's said, lifestyle modifications, such as smoking and drinking management should be a priority since these factors increase the risk of treatment failure and the appearance of second cancer. Unfortunately, preventive chemicals are ineffective and follow-up is the second crucial step. Basic imaging is usually indicated every 3–6 months after the end of treatment or clinical signs are

fibula free flap used as post-surgical reconstruction after segmental

centers with an expert team and appropriate infrastructure.

been correlated with worse outcomes [40–42].

inappropriate for microvascular surgery.

**6.2 Adjuvant treatment**

*Oral Diseases*

**7. Prognosis**

**8. Following**

**100**

The treatment outcome of oral cancer in recent decades has compellingly improved with the advancement in reconstructive surgery and adjuvant treatment. Further improvement in prolonging survival is hampered by an increase in the second-cancer incidence in long-term patients. With this in mind, oral cancer prevention is the first step, following that a requirement of enhancing awareness, promoting education, improving lifestyle and developing early diagnosis tools should have high consideration.
