A COMPARATIVE STUDY ON EVALUATION OF SERUM LDH IN MANAGEMENT OF HEAD AND NECK SQUAMOUS CELL CARCINOMA.

AIM OF THE STUDY: 
The Objective of this study is to assess the efficiency of serum lactate dehydrogenase as a biochemical marker in head and neck squamous cell carcinoma. 
MATERIALS AND METHODS: 
The study was conducted in histologically confirmed cases of head and neck squamous cell carcinoma, in department of ENT, Madurai Medical College, Madurai. Head and neck cancers is most prevent in men than women due to alcohol and tobacco chewing and is more in developing countries like India. 
This makes the need for a easy and simpler test that suggest cancer quite early before patient comes symptomatic and that can also be done during routine visit to health care facility at an affordable cost. The study included patients histologically proven to be HNSCC, AGE > AND = 30 years, consent for the study. AGE < 30 years, co-morbid conditions, carcinoma skin and thyroid, carcinoma in situ were excluded from the study. History taking, Clinical Examination were done. Serum lactate dehydrogenerase was estimated in pre treatment and post treatment phase. 
RESULTS: 
Data analysis from the study showed the following facts: 
1. serum LDH is consistently elevated in HNSCC irrespective of the site of origin. 
2. serum levels also correlate with the histological grade of malignancy. 
3. the serum levels also correlate with the disease load of the patient. 
4. LDH level also decrease to normal range in patients after treatment irrespective of modality of treatment. 
5. also used to follow up patient to detect recurrences.

A neoplasm or carcinoma is an abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of normal tissues and persists in the same excessive manner after cessation of stimuli which evoked the change 1 . Persistence of cancerous cells, even after the stimuli is removed is due to the heritable genetic change that is passed to tumor cell progeny. The genetic change leads to excess unregulated proliferation, which is also autonomous. All tumor cells have two compartments 1. Proliferating neoplastic cells which is the parenchyma 2. Supportive stroma which is connective tissue and blood vessels. Head and neck malignancy poses a significant health problem in INDIA. In INDIA population registries estimates annual incidence of 25000 new cases of carcinoma larynx alone . Head and neck malignancies have numerous hidden areas called" coffin corners" where tumor continues to grow. Eventhough premalignant lesions can be clearly identified there is a significant rate of late presentation in our country. D] Early detection and treatment is the only chance for better outcome as these tumors are aggressive compared to tumors elsewhere. The importance of early detection will help both in cure and lessening the morbidity, thereby enabling the patients to lead a qualitatively better life. The need for an easy and simple test that is suggestive of cancer quite early even before the patients become symptomatic and which can be done during routine visits to the health care facility at an affordable cost. 910 2. To assess the tumor burden or load of the patient using serum lactate dehydrogenase levels 3. To assess the response to treatment mostly radiotherapy by checking fall in serum level after radiotherapy. 4. To detect early recurrence in patients treated by radiotherapy as post radiation changes effectively mask clinical examination for recurrences. 5. To compare lactate dehydrogenase levels between various histological types of head and neck cancers. 6. To assess the relationship between serum LDH levels and degree of tumor differentiation. 7. To assess the relationship between serum lactate dehydrogenase levels and morphological type of tumor.

Materials And Methods:-
A total study of 50 proven cases of head and neck squamous cell carcinoma done in department of ENT, Government Rajaji Hospital , Madurai, Tamilnadu during the period from august 2016 to august 2017. Age and sex incidence, various presentations, symptomatology and serum values of patients pre treatment and post treatment are well documentd. Treatment modalities adopted are radiotherapy and surgery. Among the 50 cases, only 3 cases underwent total laryngectomy and remaining 47 were subjected to radiotherapy.
The clinical study includes 50 patients attending department of OTORHINOLARYNGOLOGY and surgical oncology and radiotherapy, Government Rajaji hospital Madurai. The approval of the Institutional review board was obtained.
Inclusion Criteria:-Age =and > 30 years Histologically proven to be carcinoma of head and neck Consent and willingness for participating in study Exclusion Criteria:age < 30 years carcinoma of skin and thyroid any co-morbidity lymphoma any other primary carcinoma or on treatment for any other malignancy minor, prisoner,pregnancy carcinoma in situ patients who are considered to meet the criteria of mental incapacity The study design is a case control study. the patients are divided into two groups. controls cases

Controls:-
The control group consists of 50 age matched individuals of both sexes. The control group consists of patients attending ENT OPD for problems not related to cancer. A brief clinical history and gross physical examination was done to exclude cardiac and liver disease in control group. no blood investigations other than serum lactate dehydrogenase was done in this group. Serum lactate dehydrogenase levels were taken during first visit and was not followed up with similar estimation.

Study Group [Cases]:-
The study group consisted of 50 cases of histologically confirmed head and neck squamous cell carcinoma . A thorough history and meticulous physical examination was done in all patients including indirect laryngoscopy examination and direct laryngoscopy examination.
Routine blood investigations like total count , differential count , haemoglobin % erythrocyte sedimentation rate, blood urea, sugar and serum creatinine levels were done in all patients. Urine was tested for albumin , sugar and deposits.
Radiological examinations like x-ray chest to rule out pulmonary secondaries, ultrasonogram to assess liver function and to rule out hepatic secondaries were done in all patients.

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Computerized tomography was done in appropriate cases to assess the extent of tumor , to note involvement of clinically silent areas like pre epiglottic, para glottis spaces etc and to pick up clinically silent neck nodes.
Magnetic resonance imaging was not done due to cost constraints.
All patients were subjected to pharyngolaryngoscopic examination under local anaesthesia and an accurate evaluation of tumor evaluation according to TNM staging, done by fibre optic Hopkins rod telescopes. Photo documentation was done in selected cases. Biopsy taken from tumor and sent for histopathological examination.
After a complete clinical and radiological evaluation patients were subjected to radiotherapy except for 3 patients who were treated by surgery . Patients requiring chemotherapy were not included in the study.
For all patients receiving radiotherapy serum levels were sampled before initiation of radiotherapy and then again on completing radiotherapy .For patients treated by surgery serum levels were taken before surgery and 2 weeks after surgery.

Method Of Collection And Estimation:-Collection:-
As the levels of LDH can be elevated following strenuous physical activity the samples were collected after a period of rest in a relaxed supine patient, from a peripheral vein 3 ml of blood was collected into a sterile , clean ,dry container 34 . Care was taken to avoid hemolysis during sampling , collection and transportation as hemolysed sample can give high values 35 .
Estimation:-Estimation was done immediately once the blood sample clotted as the level of enzyme falls in a stored sample. The clotted blood was centrifuged at 3000 rpm. The clear supernatant containing serum was used for the test. The procedure was perfomed in auto analyser using LDH KIT.
Observation:-In this study of 50 cases of head and neck squamous cell carcinoma who attended and got treated at Govt Rajaji Hospital Madurai, the following observations are made.
Sex The control group consist of 50 cases of 40 males and 10 females , average age for males 58 years and for females 50 years.      From supraglottic tumour, pre treatment and post treatment values we arrived at a conclusion that pre treatment serum LDH was higher and dropped to lower values after treatment whatever may be the modality of management, surgery or radiotherapy. One another factor which has been arrived at is T4 stage showed increased pre treatment serum LDH value than T1 stage. Similarly pre treatment serum LDH value showed a progressive increase and when we move through T1 to T4. That shows serum LDH increases with increase in tumour staging. Also seen poorly differentiated tumours showed high serum LDH values than moderate and well differentiated tumours. Except female patients in carcinoma supra glottis, all others were chronic smokers and alcoholics. Only duration and quantity of exposure varies.

Glottis:-
Out of 11 cases of proven carcinoma glottis, 1 patient 50 years male, who is a proven moderately differentiated carcinoma T3 stage whose pre treatment value was 302 IU/litre and post surgical value was 186 IU/litre. He underwent total laryngectomy with partial thyroidectomy. Among the remaining 10 cases, 5 were well differentiated, 4 were moderately differentiated, 1 poorly differentiated. Among 11 cases 6 were T3, 3 were T2, 1 belongs to T1. Among the 11 patients only 6 were chronic smokers and alcoholics, remaining 5 were occasional smokers and social alcoholics.

Carcinoma Subglottis:-
Only one female among the 50 patients proved to be squamous cell carcinoma sub glottis. Staging T2N0M0 moderately differentiated squamous cell carcinoma. Her pre treatment serum LDH showed 359.11IU/litre and post treatment was 220.16. She was not a tobacco chewer or an alcoholic.
Carcinoma Hypopharynx:-9 cases of carcinoma hypopharynx was studied. Only 1 was female patient with moderately differentiated squamous cell carcinoma. Tumour staging was T2. Her pre treatment LDH showed 386.26IU/litre and post treatment 160.18 IU/litre. Only one patient belongs to T4Bstage, 3 patients were of T3 stage, 4 patients belonged to T2 stage. This shows tumours of hypopharynx present for treatment at a relatively advanced stage. Presentation at T1stage was rare. Patient usually comes for treatment when symptoms of dysphagia progresses. Commonest presentation of CA hypopharynx is T2 stage with no node. Pyriform sinus tumour present with cervical lymphadenopathy than with any other subsite.
Head and neck tumours are common in INDIAN sub continent. In the above study, percentage of carcinoma supra glottis is common followed by carcinoma oropharynx, carcinoma glottis, hypopharynx and last sub glottis. Average age of malignant tumors in male is 60 years and female it is 47 years. The reason for which male being more commonly affected than female is increased habit of smoking, alcohol with tobacco chewing in males compared with females. Symptoms with which head and neck malignant tumour patients presented to OPD includes dysphagia, change in voice, difficulty in breathing, hoarseness of voice, cervical lymphadenopathy.
Out of the 50 patients in this study, totally 3 patients underwent surgery, remaining 47 underwent radiotherapy. There is no difference in serum LDH reduction level in both surgery and radiotherapy patients. Similarly for well, moderately or poorly differentiated tumours also the reduction in serum LDH level showed no correlation with the differentiation or stage of tumour.

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Malignancies of head and neck constitute 50 -70 % of cancers diagnosed in INDIA . The overall survival rate for some subsites is less. The poor survival is contributed to late presentation , poor accessibility ,lack of awareness.
The key factor in increasing survival is early detection and treatment of the disease and recurrence . This study attempts to enlighten a parameter that would facilitate the above idea.
In the present study of head and neck squamous cell carcinoma ,the mean serum LDH level in control group was 236 IU/L for males and 198 IU/L for females. This is within the normal lab control of 120 -246 IU/L. in the study group the pre treatment level of serum LDH was 331.92 IU/L for radiotherapy group and 343 IU/L for surgery group .These values are grossly above the normal level. The post treatment values of serum LDH for radiotherapy and surgery group are 206.42 IU/L and 240.66 IU/L respectively. These values are within the normal lab control values.
This proves the fact that serum LDH is elevated in patients with head and neck malignancy .The study shows serum LDH levels decrease to normal level following curative therapy irrespective of the modality of therapy.
From this study we also see the pre treatment LDH levels vary with the degree of differentiation of tumor. the well differentiated tumors have mean serum LDH levels of 312.88 IU/L, moderately differentiated 327.07 IU/L, poorly differentiated tumors 393.14 IU/L. this shows the levels increase with increasing grades of tumor.
Another factor derived from the study is serum LDH levels also correlate with size of the tumor .t2 stage exhibit a mean of 367.53 IU/L compared to t1 stage which showed mean of 286 IU/L pre treatment. Similarly t4 stage showed pre treatment mean of 363.66 IU/L compared to 312.37 IU/L in t3. Serum LDH seems to correlate with size of the tumor as larger tumor have more cells from which enzymes might leak into blood or larger necrotic fraction so that the enzymes leak into blood as a result of cell break down.
One other interesting factor to emerge from the study is serum LDH levels also correlate with dissemination of disease. The levels are higher in patients having metastasis to cervical node than those with No neck. In this study 29 patients had cervical node metastasis clinically and none of the patients had systemic metastasis which is also uncommon in head and neck cancers.remaining 21 patients had no clinical and radiologically detectable metastasis. The serum LDH levels for metastatic group was 342.19IU/L and for non metastatic group was 321.55IU/L . Other serum enzymes like serum adenosine deaminase and phosphate hexose isomerase does not show this correlation.

Conclusion:-
From this study, the following conclusions are arrived 1. Serum LDH is consistently elevated in head and neck squamous cell carcinomas.
2. The rise in serum level is irrespective of the site of origin of tumor.
3. The enzyme increase in other histological types is not evaluated in this study 4. The rise in enzyme level increases with the size of the tumor and shows higher levels in larger tumors compared with smaller ones. 5. The serum LDH levels also correlate with the histological grade of malignancy . Poorly diifferentiated carcinoma shows largest level followed by moderately differentiated and then well differentiated tumors. 6. The levels are significantly higher in patients with metastasis than those without metastasis. 7. From this study it is concluded that serum LDH levels decrease to within normal range in patients treated by curative therapy . All patients show significant fall in levels following radiotherapy or surgery. 8. The fall in level is irrespective of the curative treatment modality. 9. Morphological type of tumor does not show any correlation with enzyme levels 10. As the enzyme level falls with therapy ,this could be used for follow up of the patient to detect recurrences. 11. This test can be used to screen high risk patients at primary care level since the procedure is easy and cost effective.
It is said cancer is very easy to see than to foresee. By periodically screening persons with risk factors with simple procedures malignant changes can be detected at incipient stage. When a malignancy is still cytological than histological cure can be given. Smoking and alcohol were found to be the main etiological factors. Health education and periodic screening will help early detection of head and neck malignancy and will go a long way in men's quest to weed out diseases and improve the quality of life .