Study on topographical distribution of carcinoma larynx

Objectives: To find out the sites of involvement of carcinoma larynx. Methods: A cross sectional study was carried out from January, 2006 to December, 2007 at the Department of ENT and Head-Neck Surgery of Dhaka Medical College Hospital, Dhaka. This study included 147 cases with of carcinoma larynx. Results: Among 147 cases in this study near age was 54.53 years the pearl incidence was 6th to 7th decade; male: female rate 28.4: 1. Majority of case were related to cultivation (42.6%), came for rural area (66.7%), socioeconomic group (68%) and illiterate (49.7%). Regarding habit most of them were more than one habits (87.7%) patients were smokers, duration of smoking habit varied from 2 years to more than 40 years and per day consumption from 3-32 sticks. 100% of female had the, habit of betel leaf chewing in this study. The common symptom was hoarseness of voice (93.8%) followed by dysphagia (61.6%) respiratory distress (52.4%), earache (6.8%) cases, haemoptysis and neck pain in small proportion. Indirect larygoscopic examination: Supraglottic carcinoma extension to one dial wall of pyriform fossa and valecular / bare of the tongue were present in (11.5%) and 8.7 cases respectively. 73.4% cases were more then one subsites involvement. Impaired vocal cord morbidity was found in 30.9% and fixed cord was 49.6%, 55.2% cases were airway inadequate, nodal involvement was 46.9%, 98.6% nodal involvement in supraglotic region, 65.2% were NI stage followed by N2 (21.7% and N3 (13%) distribution of the carcinoma larynx were supraglottic 74.10 glottic 25.10% and subglottic 0.70% more than one insite involvement were 88%, in supraglottic epiglottis 5.5%, any epiglottic folds 4.6% or glend 0.9% and ventricular bands were 0.9%. In the subsite of the glottic carcinoma glottic proper 37.8% followed by more then one insite (32.4%) anterior commissure 18.4% and posterior commissure 10.8%, 55% of the patient were Grade II and 49.6% were stage III. Conclusion: Incidence of supraglottic carcinoma was more common, involvement of more than one single site also common.

73.4% cases were more then one subsites involvement.Impaired vocal cord morbidity was found in 30.9% and fixed cord was 49.6%, 55.2% cases were airway inadequate, nodal involvement was 46.9%, 98.6% nodal involvement in supraglotic region, 65.2% were NI stage followed by N2 (21.7% and N3 (13%) distribution of the carcinoma larynx were supraglottic 74.10 glottic 25.10% and subglottic 0.70% more than one insite involvement were 88%, in supraglottic epiglottis 5.5%, any epiglottic folds 4.6% or glend 0.9% and ventricular bands were 0.9%.In the subsite of the glottic carcinoma glottic proper 37.8% followed by more then one insite (32.4%) anterior commissure 18.4% and posterior commissure 10.8%, 55% of the patient were Grade II and 49.6% were stage III.Conclusion: Incidence of supraglottic carcinoma was more common, involvement of more than one single site also common.

Introduction:
The larynx is the most common site for primary malignant tumour in head and neck region.
International Union against cancer (UICC) and American joint committee (AJCC) on cancer in 1978 divides the larynx into 3 regions a) supraglottic b) Glottic and c) subglottic and carcinoma in supraglottic region is again sub divided according to site of origin, 1, 2 carcinoma of i) laryngeal surface of epiglottis, ii) aryepiglottic fold, iii) arytenoid iv) false cord and v) ventricle.Carcinoma in glottic region is subdivided according to its location, carcinoma of i) volcal cord ii) anterior commissure and iii) Posterior commissure.Carcinoma in subglottic region involves the area from the inferior border of the vocal cord to lower border of the cricoid cartilage including the areas caudal to the anterior and posterior commissure. 3,4  American cancer society estimated approximately 12000 new cases of laryngeal cancer in USA in 1996. 5A higher incidence of laryngeal cancer has been reported from Asian population.Study in our country also showed that the number of patients suffering from laryngeal carcinoma is increasing gradually, in a study in Dhaka Medical College Hospital, it was seen that 35.32% of all body cancers was in head and neck region and carcinoma of larynx was the commonest in head and neck region (31.58%). 6tention must be paid to the accurate assessment of the location of the tumour because of the wide variation in the treatment planning and disparity of prognosis among the tumour involving different regions and even different subsites of the same region within larynx. 7Although tumour of the same site may often have various biological potentials for malignancy, the site of laryngeal carcinoma is an important initial prognostic factor, because it comprises the possible way of extension of the primary tumour and modalities of metastasizing. 8e present study is done to outline the distribution of carcinoma of the larynx according to frequency in different anatomical regions & sites.The study results will provide us some knowledge to early diagnosis, treatment modalities and prognosis accordingly.The study will also help to find out the association of causative factors i.e. smoking, tobacco, betel-nut chewing, alcohol consumption etc. and carcinoma of larynx, because no single specific factor for laryngeal carcinoma has been cited.

Methods:
Methods of study: Patients were diagnosed as cases of laryngeal carcinoma by detailed history, general physical examination, and examination of neck, chest and abdomen.Then indirect laryngoscopic examination was performed in all cases and FOL in difficult cases for indirect, direct laryngoscopy and CT scan.

Type of habit
No  Other studies also support that the peak incidence of laryngeal carcinoma is at the 6th or 7th decade. 11 -14In this study male 96.6%, female 3.4% and male female ratio were 28:4:1. 15,16 here is significant association between male & occurring of laryngeal carcinoma (P<0.001).Most of the subjects came from rural areas (66.7%) and from a low socio economic status (68%), which is consistent with other studies. 16,17 jority of the subjects were related to cultivation (45.6%) in occupational analysis, which is consistent with the findings of another series. 16Lack of health care facilities, have a synergistic effect along with smoking in development of carcinoma of larynx. 18jority of the study subjects were smokers (87.7%), other personal habits were betel leaf chewing (55.1%) & chewing tobacco (57.1%) and alcohol consumption only (2.6%).In this series we found duration of smoking maximum in 15-30 years which was consistent with, where maximum duration of smoking was 20-30 years.There is significant association between smoking & laryngeal carcinoma (P<0.001).
In this study we have seen that chewing habit of betel leaves with other ingredient (shada, betel nut, lime, jarda etc.) indifferent combination of proportion is (55.1%),along proportion of study subject had chewing habit along with smoking (44.9%).So that there is a association of smoking and tobacco chewing habit with development of laryngeal carcinoma. 19 the context of our country development of supraglottic carcinoma may be related with poor nutrition with personal habit like, smoking and chewing habit of betel leaves with various ingredients, these chemical/physical ingredients are irritants to the mucous membrane of upper aero-digestive tract causing supraglottic carcinoma more common. 20,21,22 Ihe Western countries cause of high incidence of glottic carcinoma is due to more consumption of alcohol.But due to Muslim country alcohol is prohibited in Bangladesh, for this reason there may be lower incidence of glottic carcinoma.
Majority of the patient attended in hospital during a time interval of 6 months or more Most of the study subjects presented with more than one symptom, which were change of voice (93.8), difficulty in swallowing (61.6%), difficulty in respiration (52.4%) and others, almost similar observation was found by previous studies. 24 the glottic carcinoma, the commonest symptoms was the hoarseness of voice found in this series.(a)There is significant association between hoarseness of voice and glottic carcinoma (P<0.001).In previous study shows that change of voice was the common symptoms in case of glottic carcinoma but it was also leading symptoms in case of supraglottic carcinoma.
Difficulty in swallowing was common symptoms in this study which was more significant in supraglottic carcinoma (P<0.001) which is consistent with previous studies. 26e finding of indirect laryngoscopy was confirmed by direct laryngoscopic examination.We found incidence of supraglottic carcinoma (74.1%) was predominant over glottic carcinoma (25.2%) but only one patient was affected by subglottic carcinoma (0.7%).Similar observation was found in previous studies. 27So occurrence of supraglottic carcinoma is more common and it is statistically highly significant (P<0.001).
Lymph node involvement was found in 69 (46.9%) patients.Among them most of the subjects were supraglottic carcinoma (98.6%) and only one was glottic carcinoma.)).This result also similar to other study, which was not significant with our series (P>0.05). 29 this study regarding staging of carcinoma of the larynx most of the patients present at advanced stage, mostly in stage III (49.6%), followed by stage II (32.6%), stage I (13.0%) and stage IV (4.8%).So that majority study subjects were squamous cell carcinoma stage III.
This observation is similar to the studies, 30 but differ with western studies. 31,32 taging is more important for better treatment modalities and prognostic value.From this study we have seen majority of carcinoma of larynx is found in advanced stage as they present late & more common in supraglottic.

Conclusion:
Incidence of supraglottic carcinoma is more common, involvement of more than one subsites also common.Hoarseness of voice is the commonest presenting symptom in laryngeal carcinoma.
Incidence is more in male, smoking is the commonest predisposing factor.Most of the cases present at an advanced stage.Extensive studies are required for better evaluation.Progressive intermittent hoarseness of voice more than 15 days should evaluate by otolaryngologist.
Histopathological examination was done for confirmation of malignancy and histological grading.Staging was done by grouping together of TNM features.Nodal status was determined by clinical examination.Stage I & II were marked as early stage.Stage III & IV were marked as advanced stage.

Table - V
Symptoms by site of carcinoma of the larynx (n=147)

Table - X
Sub-site involvement of glottic carcinoma (n=37)