Oral Oncology 34 (1998) 472±475
Surgical management of the neck in squamous cell carcinoma of the ¯oor of the mouth A. Zupi*, L. Califano, G.M. Mangone, F. Longo, P. Piombino Department of Maxillofacial Surgery, School of Medicine and Surgery, ``Federico II'' University of Naples, Naples, Italy Received 9 February 1998
Abstract Nodal involvement in squamous cell carcinoma considerably lowers survival rate. Despite its importance, neck management has still not been adequately explored. The Authors have retrospectively reviewed the records of 112 cases. Unilateral N+ were treated with a homolateral therapeutic and a controlateral prophylactic neck dissection; bilateral N+ were treated with a bilateral therapeutic neck dissection. On ®rst observation the majority of cases (66.1%) were T1±2. N+ patients accounted for 45.5%. Among Nÿ patients, 21.3% of occult nodal metastases were observed. The 5-year survival rate was 52.7%. With N+ lesions, a radical neck dissection should be performed; the dissection should be performed bilaterally. With Nÿ lesions a prophylactic modi®ed radical neck dissection is recommended in T2±4 lesions. # 1998 Elsevier Science Ltd. All rights reserved. Keywords: Oral cancer; Floor of the mouth; Nodal metastases; Neck dissection
1. Introduction Nodal metastases frequently occur with squamous cell carcinoma (SCC) of the ¯oor of the mouth (from 11 to 53%, depending on the T stage) [1±3] and nodal involvement considerably lowers survival rate . Neck treatment thus has a prominent role in the management of the patient with SCC of the ¯oor of the mouth. Despite the high incidence, poor prognosis and abundant literature, correct surgical management of these lesions has still not been adequately explored. To help shed light on this problem the records of 112 consecutive cases of SCC of the ¯oor of the mouth have been retrospectively reviewed. 2. Patients and methods The records of 112 consecutive patients with SCC of the ¯oor of the mouth treated between 1975 and 1992 at the Department of Maxillofacial Surgery of the School of Medicine and Surgery of the ``Federico II'' University of Naples, Naples, Italy, were retrospectively reviewed. * Corresponding author. Via Michelangelo Schipa, 115, I-80122 Naples, Italy. Tel.: +39-81-7462075; fax: +39-81-5453491; e-mail: [email protected]
Site and size of the tumour together with nodal status, according to the UICC classi®cation , were observed. Lymph node involvement was evaluated by dividing the lymph nodes of the neck into ®ve regions as recommended by Shah and Anderson . All patients underwent radical resection of the area involved. The extent of the resection was determined by the extent of the tumour; a margin of 1 cm of noninvolved tissue was generally considered to be safe practice. With unilateral N+ a homolateral therapeutic and a controlateral prophylactic neck dissection were performed; with bilateral N+, a bilateral neck dissection was performed; in Nÿ patients, neck management varied with each case. All patients were followed up for 5 years or more. The terms used for neck dissection are in accordance with the Medina classi®cation . 3. Results Results are summarised in Figs. 1 and 2. Males were more frequently aected (67%), with a male:female ratio of 2:1 (75:37 cases). Peak incidence (34.8%) was found in the age group 41±60 years with a total of 39 patients (34.8%). On ®rst observation, the majority of
1368-8375/98/$Ðsee front matter # 1998 Elsevier Science Ltd. All rights reserved. PII: S1368 -8 375(98)00046 -3
A. Zupi et al./Oral Oncology 34 (1998) 472±475
Fig. 1. Distribution according to sex and age.
Fig. 2. Distribution according to T and N staging. cN+ (clinical N) indicates the patients preoperatively N+ staged, while pN+ (pathological N) indicates the percentage of postoperatively staged N+.
cases (41 patients) were T2 (36.6%), whilst T1, T3, and T4 accounted for 33, 32, and six cases, respectively. N+ patients totalled 51 (45.5%); cervical region I was more frequently involved with 51 cases (45.5%); regions II and III were involved in 39 cases (34.8%); region IV was involved in 18 cases (16.1%); ®nally, region V was involved in three cases (2.7%). Among the 61 Nÿ patients (54.5%), 13 cases of occult nodal metastases (21.3%) were observed. Among the 51 N+ patients, 32 cases were preoperatively bilateral (28.6%) whilst 19 cases were N+ unilateral (17%). After surgery, controlateral occult metastases were found by the pathologist in four cases (3.6%). The overall 5-year survival rate was 52.7%. Speci®cally, N+ and Nÿ patient survival rates amounted to 25.5 and 75.4%, respectively (Fig. 3). 4. Discussion SCC of the ¯oor of the mouth frequently causes nodal involvement: its role is important and prognosis is
heavily in¯uenced. In actual fact, the neck is the most common site of failure [2,3,7]. In our experience, global N+ rate was 45.5%. N+ usually occurs in regions I, II, III, and IV (45.5, 34.8, 34.8, and 16.1%, respectively), whilst region V is rarely involved (2.7%). Incidence of occult metastases may be as high as 30% [2,3,8] with a similar distribution; Byers et al.  and Shah et al.  report occult metastases mainly in regions I±III (from 7 to 64%), and very seldom in regions IV and V (from 0 to 2%); in our experience, these rates were 14.6, 14.6, 6.7, 1.1 and 0%, in regions I±V, respectively. Bilateral and controlateral involvement are quite frequent (3.4 and 2.2%, respectively). With N+ lesions a neck dissection should certainly be performed; it should be a bilateral dissection because of the high incidence of controlateral metastases , and it should be extended when there are signs or the suspicion of extracapsular diusion. As to the choice of neck dissection, we underline the high rate of nodal involvement of nodes which are usually preserved . In our experience, lower jugular lymph nodes (region IV) and neck posterior triangle lymph nodes (region V) were involved in 16.1 and 2.7%, respectively; these observations suggest a radical neck dissection. As regards Nÿ lesions, treatment strategy of the negative neck is still under debate and may vary from observation alone, prophylactic neck dissection in advanced tumours (T3±4), to neck surgery in all patients. In our opinion, the high incidence of occult metastases (21.3%) and the well-recognised poor salvage rate among patients who develop cervical metastases after primary therapy [10,11] undoubtedly suggest prophylactic treatment. Moreover, Shah et al. , in initially staged N0 patients who developed an N+ neck after surgical treatment of T, report the presence of cervical metastases in levels IV and V, which are not usually involved. Regarding `when' and `how' to treat the tumour, in T2±4 lesions we observed a high incidence of occult metastases (52.4%) proving that a prophylactic neck dissection is mandatory; in T1 lesions occult metastases are quite uncommon (6%) and a close follow-up should be sucient to manage these patients. As to the choice of neck dissection, we underline the low rate of nodal involvement of lower jugular lymph nodes and neck posterior triangle lymph nodes , involved in 1.1 and 0%, respectively; these observations suggest prophylactic treatment with a supraomohyoid neck dissection, preserving regions IV and V. In conclusion, a neck dissection is clearly required in N+ tumours though precisely which dissection depends on the characteristics of the lesion. The dissection should be a modi®ed radical; if extra-capsular spread or tumoral diusion is present, a radical neck dissection should be performed, sacri®cing the structures involved.
A. Zupi et al./Oral Oncology 34 (1998) 472±475
Fig. 3. Survival in pN0 (3a) and pN+ (3b) patients.
With Nÿ lesions, management is controversial. There is, in fact, a great dierence between N grade (57.1%) and Np grade (71.7%) due to the high rate of occult metastases. Thus, we suggest a prophylactic selective supraomohyoid neck dissection; the dissection should be homolateral in the case of lateral lesions and bilateral in the case of median lesions. As far as postoperative radiotherapy is concerned, it should be performed basing the decision on certain clinical and pathological ®ndings, such as multiple positive nodes, the presence of extracapsular spread or no radical surgery [3,12].
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