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LETTER TO EDITOR
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Year : 2009  |  Volume : 46  |  Issue : 2  |  Page : 176--177

Enigma of the unknown primary in head, neck cancers

R Kazi 
 Head and Neck Unit, Royal Marsden Hospital, 203 Fulham Road, London SW3 6JJ, United Kingdom

Correspondence Address:
R Kazi
Head and Neck Unit, Royal Marsden Hospital, 203 Fulham Road, London SW3 6JJ
United Kingdom




How to cite this article:
Kazi R. Enigma of the unknown primary in head, neck cancers.Indian J Cancer 2009;46:176-177


How to cite this URL:
Kazi R. Enigma of the unknown primary in head, neck cancers. Indian J Cancer [serial online] 2009 [cited 2021 Jan 19 ];46:176-177
Available from: https://www.indianjcancer.com/text.asp?2009/46/2/176/49162


Full Text

Sir,

The authors and IJC must be commended for publishing this interesting retrospective, cross-sectional study in an a rather unique cohort of patients. [1]

The etiology of the unknown / occult primary has been a subject of much debate and discussion over the years. It is now referred to by the term 'Carcinoma of unknown primary site (CUP)' and is defined as a biopsy proven cancer of the neck, which even after a complete clinical and radiographical workup, reveals or yields no demonstrable primary tumor. [2],[3] There is much controversy in the literature as regards its development and origin. Some suggest the CUP is a result of an undetected primary tumor that is often detected later on in the clinical course. Others strongly believe that the primary tumor undergoes immune-mediated spontaneous regression, while the metastatic tumor escapes immune surveillance. These patients should be investigated in a thorough and logical manner, often employing an algorithm-like approach. Globally the rate of CUP is on the decline. This most likely represents the identification of more unknown primary tumors as a result of improved imaging and clinical evaluations. Several studies have demonstrated that Fludeoxyglucose F 18 Injection-positron emission tomography (FDG-PET) computed tomography (CT) can detect a primary lesion in 21 to 47% of the cases. [4] By definition and as per AJCC staging, CUP is T0 and N+ as a rule and all patients should be considered stage III if they have N1 disease and stage IV if they have N2 and N3 disease. [2],[3] The survival and prognosis of a CUP patient is affected often in head, neck cancers by a variety of factors including patient co-morbidity, performance status, nutritional status, and immune response. But perhaps the most important is the nodal location and presence of an extra-capsular spread. Treatment is based on whether the disease is early or advanced in its presentation. Early disease is treated with a single modality either neck dissection or radiotherapy, with the advanced disease often requiring a combination approach.

While this study does in part come across as a retrospective audit of the treatment protocol followed by a leading cancer institution, nevertheless this is a fine effort. This, especially considering that there is a great paucity of literature in this field in India. [5] No doubt this is surprising and disappointing considering the magnitude of head, neck cancer load in the Indian subcontinent. Although I must add that I do not think that the presentation and outcome will be much different in Indians. Perhaps it would have more been interesting if the authors would have tried to extend the study to year 2000 -2007, so as to be more current. This would have provided valuable insight into the effect of PET-CT on tumor detection and its prognosis. However, we still need more such studies and institutions should emphasize and focus on this. A good first effort by the authors, but can be improved further by increasing the patient numbers and bringing it to a more current date, as the article, as of now, does not add to the literature already present.

References

1Mistry RC, Qureshi SS, Talole SD, Deshmukh S. Cervical lymph node metastases of squamous cell carcinoma from an unknown primary: Outcomes and patterns of failure. Indian J Cancer 2008;45:54-8.
2Issing WJ, Taleban B, Tauber S. Diagnosis and management of carcinoma of the unknown primary in the head and neck. Eur Arch Otorhinolaryngol 2003;260:436-43.
3Jereczek-Fossa BA, Jassem J, Orecchia R. Cervical lymph node metastases of squamous cell carcinoma from an unknown primary. Cancer Treat Rev 2004;30:153-64.
4Miller FR, Hussey D, Beeram M, Eng T, McGuff HS, Otto RA. Positron emission tomography in the management of the unknown primary head and neck carcinoma. Arch Otolaryngol Head Neck Surg 2005;131:626-9.
5Shenoy AM, Hasan S, Nayak U, Anantha N, Reddy BK, Kannan V, et al. Neck metastasis from an occult primary--the Kidwai experience. Indian J Cancer 1992;29:203-9.