HEAD & NECK CANCER PART-6
(All the articles published in past are available at www.shyamhemoncclinic.com/blog/)
Question: Dr. Chiragbhai, thank you for making following important points in last discussion: BIOPSY is MANDATORY before starting treatment. CANCER DOES NOT SPREAD DUE TO BIOPSY. Specialized head and neck cancer surgeon and good reconstruction/plastic surgeon are important while choosing surgeon. There is no role for DEBULKING surgery in this region. If complete resection with negative margins is not feasible, surgery should not be attempted.
Would you like to discuss any other important principle of surgery?
Ans: Yes, another important aspect is role of neck dissection. As we have seen earlier, these tumors tend to spread to specific regions of neck lymph nodes. Removing these lymph nodes serves two purposes: one is to remove disease in lymph nodes and second is to detect occult disease as part of staging.
There are different types of neck dissections.
A RADICAL neck dissection is one in which all five node levels are removed en bloc, with 3 important structures. These 3 are: sternocleidomastoid muscle, internal jugular vein, spinal accessory nerve. This procedure has a high risk of postoperative shoulder pain and weakness. MODIFIED RADICAL neck dissection is one where at least one of these 3 important structures is preserved, without reducing disease control rate.
SELECTIVE neck dissection involves removing less than 5 node levels, depending on site of tumor. This is generally done when there is high probability of spread based on clinical criteria (over 15-20%) but clinical examination and imaging studies do not indicate lymph node spread. Positive nodes detected in this manner, having occult metastases, have a bearing on staging and decision about postoperative radiotherapy.
Que: Ok. It is obvious that patients with clinically positive nodes need neck dissection. But isn’t it too much to offer neck dissection for those who have negative nodes on examination and CT scan as well? Most of these patients will have negative nodes even after surgery.
Ans: Good question, and a difficult one to answer definitively. However there is a very good recent study, published in NEJM May 31st, 2015 issue, addressing exactly this question. Importantly, and proudly, it is from an Indian center, Tata Memorial Hospital, where over 500 patients were studied in a randomized controlled trial, offering elective node dissection for early stage tumors T1 or T2 of oral cavity Versus node dissection only after nodal relapse. 85% of patients enrolled were tongue cancers. Interestingly, they found significant improvement in overall survival and risk of relapse with elective node dissection i.e. use of neck dissection even with clinically and radiologically negative nodes. We have to await expert comments on how to interpret these results for routine practice. But it does support role of elective neck dissection, for most patients, at least for oral cavity. Morbidity of this procedure will however continue to raise debate about its routine applicability on a larger scale in community practice.
Que: This is wonderful news. Indian study published in the most prestigious medical journal, and that too answering a very India relevant question. We should have lot more such studies. Can we talk about next most important modality Radiotherapy in head and neck cancers?
Ans: Yes. Some of the details of surgery will be covered in site specific discussion. Now as we have discussed earlier Radiotherapy has replaced surgery in few sites. And in many sites, it is important postoperative therapy. Radiotherapy by itself can be used for very early tumors, such as T1 larynx. However in general, it has to be combined with chemotherapy or used after surgery for curative treatment. By itself, it is not a sufficient treatment with larger tumors beyond T1 in general.
Postoperative radiotherapy is generally started 4 to 6 weeks after surgery. It is commonly given 5 days per week, with each day about 1.8 to 2.0 Gy dose. Total dose given is about 50-65 Gy, with higher dose for involved sites, and lower dose for uninvolved sites. Thus it is usually a 5-7 weeks treatment.
It is given as outpatient. Radiotherapy machine looks almost like a larger CT scan machine, and delivers rays to the tumor without touching the patient. Precision in delivery of radiotherapy is very important. Newer machines and trained radiation teams (radiation oncologist, physicist, technician etc) ensure the precise delivery. High quality softwares and other safeguards used now reduce chance of human error to nearly zero. It also reduces radiation to nearby normal tissues, thus allowing delivery of larger doses, with less side effects. All new centers use linear accelerator, not cobalt, which also improves radiation delivery.
When used as primary modality, radiation dose is 70 Gy or greater.
June 11th 2015. Dr. Chirag A. Shah; M.D. Oncology/Hematology (USA), 079 26754001. Diplomate American Board of Oncology and Hematology. Ahmedabad. firstname.lastname@example.org Shyam Hem-Onc clinic. 402 Galaxy, Near Shivranjani, Opp Jhansi ki Rani BRTS, Ahmedabad. www.shyamhemoncclinic.com