**4.3 Nodal metastases in neck**

Almost all patients with hypopharyngeal carcinoma have a high incidence of lymph node metastasis in the neck [30, 111]. Pyriform fossa cancer has the highest cervical metastasis rate (> 75%), while the lymph node metastasis rate of the posterior pharyngeal wall and posterior ring carcinoma is currently between 30% and 60% [29, 30, 111, 112]. For clinically negative (cN0) neck, the high-risk lymph node group must be included in the scope of dissection. Bilateral neck dissection should be considered with the tumor across the midline and tumors located in the

*Hypopharyngeal Cancer: Staging, Diagnosis, and Therapy DOI: http://dx.doi.org/10.5772/intechopen.97462*

posterior pharyngeal wall, medial Pyriform wall, or posterior annular region [96, 111]. In the cN0 cases, most of the lymph nodes with positive pathological examination were located in levels II and III of the lateral neck [46, 111, 113, 114]. Thus levels II to IV should be taken into consideration for elective neck dissection in the CN+ patients, despite the low incidence of metastases at levels I and V, the cutting of levels I through V is incorporated into an overall neck dissection for reducing relapses in a node. The internal jugular vein (IJV), sternocleidomastoid muscle, and accessory nerve are recommended to be preserved and attacked directly by cancer.

Paratracheal (level VI) and retropharyngeal nodes must be brought to attention because of The risk of tumor invasion [46, 115]. Paratracheal positive nodes (level VI) are frequently involved by tumors located in the pyriform apex or post-cricoid area [111, 116–119]. A series of reports by Chung et al. poses a 27.9% occult metastasis rate in IV nodes with a much worse prognosis (26% vs. 55% 5-year diseasespecific survival) [119]. So paratracheal node dissection should be strongly involved in this crowd both for the thoroughness of removing all tumor and strict disease staging. The retropharyngeal nodal disease is common in lateral pyriform and posterior pharyngeal, existing in 40% of advanced patients [120]. Retropharyngeal nodes should be taken into adjuvant radiotherapy in the setting of unremovable surgically. In advanced stages, these positive nodes clinically/radiographically may be an indication for non-surgical treatment [120].

#### **5. Surveillance, and recurrent**

Due to most tumors relapse within two years after initiate treatment, rigorous surveillance should be followed three months after treatment until two years and every six months for 3–5 years to screen early local recurrence and second primary tumors [121–123]. A favorable scanning should involve a combination of history, physical, endoscope, images (CT, MRI, PET/CT), and biopsy [124]. For suspicion cases, repeated biopsies are necessary for positive results. PET/CT has been demonstrated to be more accurate than CT/MRI for screening falsepositive results [125, 126]. Surgery is considered an optimal option for recurrent cases (especially small recurrent). For unresectable recurrence or metastatic, re-irradiation or re-irradiation+chemo is one selection with improving median survival. Meanwhile, related toxicities cannot be ignored, with complications range from 9 to 32% in adjuvant chemotherapy cases [127, 128]. Therefore, the multidisciplinary team must seek a balance between the serious toxic reactions and the rescue therapy while paying attention to the progress of the disease in the long term.

There are not many options available for recurrent and metastasis, so it is urgent to develop new targeted agents in this population. The innovative drugs may be proved as another promising avenue for recurrence and metastasis. A variety of molecular targeting drugs are developed in the exploratory stage. These drugs have anti-cancer affection on aberrantly expressed intracellular proteins. In recent years, immunotherapy has been proved to ameliorate overall survival over standard, single-agent therapy for platinum-refractory cases [129, 130]. Anti-programmed cell death 1 (PD-1) therapies were assessed as a treatment for platinum-refractory recurrent and/or metastatic head and neck squamous cell carcinoma (HNSCC). Meanwhile, a small number of patients with the PD-1 approach acquire lower toxic effects than traditional therapies. Immunotherapy brings hope to this subtype of treat-limited patients [130, 131].
