Recurrent differentiated thyroid cancer: to cut or burn

Abstract

The term “relapse carcinoma” is used improperly to indicate either a local or loco-regional relapse or a systematic metastatsis [1]. Local relapse (LR) after thyroidectomy for cancer is “the repetition of the neoplastic lesion in proximity of the previous intervention of excision” [2]. According to Duren [3] relapses of thyroidal carcinoma need to be classified as: local (LR): that may present itself in the residual thyroid lobe or in the thyroid bed where surgery was performed; loco-regional (RLR): that may present in the cervical lymph nodes of the central compartment or lateral-cervical nodes; and metastasis in distance (MD). The MD are frequently synchronous with LR or RLR; they have haematogenous genesis and concern most frequently the lungs and skeleton. There is controversy over how to catergorize the relapse in the thyroidal bed with infiltrations of neighbouring organs (periodontal structures muscles, thyroidal cartilage, cricoid, laryngeal nerves, etc. and the neighbouring organs oesophagus, trachea, larynx). As per the classification proposed by Duren [3] these should be considered as LR, whereas according to Mozzillo and Pezzullo [1] they are categorised as RLR. The RLR at the level of the cervical lymphnodal stations represents an ulterior problem: are these true relapses, residual cancer, or recurrence in progression? Caraco [4], in his report to the ninety-fourth Congress of the Italian Society of Surgery, specified that local recurrences are only those recurrences that are characterized by the appearance of neoplastic tissue in the thyroidal lodge, in the residual parenchyma, and in the adjacent structures, excluding the lymph nodes [5,6]. In nearly 53% of cases the relapse is reported in RLR, in 28% in LR, and in 13% the MD is present of these 6% of cases have mixed relapses [7]; the prognosis of LR is however, better than that of the others [8]. The differentiated tumors of the thyroid are slow growing and due to this rarely reach notable dimensions or result in metastasis in lymph and/or haematic systems [2]. Only 10% of patients die from differentiated thyroid cancer [9]. Most of the local relapses occur within the first five years of the excision of the primary cancer [5,6,10-12], however, the recurrence can occur as late as 20 years after the initial diagnosis and treatment [13]. An accurate evaluation of incidence of LR is possible solely with a considerable number of treated patients and lengthy follow-up that is not available at most centres and hence this kind of information can be obtained from the date from centres that have high volume of thyroid carcinoma and good follow-up like Mayo Clinic or Lahey Clinic [5,6,13] or through observational studies at several other medical centres [14]. Currently relapses represent a rare event in patients who undergo removal of thyroidal carcinoma (3-13%) [5,6,10-12,15-17]. This is due to the ever increasing frequency of total thyroidectomy for management of cancer [18]. The complete excision of the thyroidal parenchyma prevents local recurrence. Giovanni Razzaboni in “Treatise on Prognostic Surgery” (1938) stated that “The most rational operating method, so long as not free from grave consequences of another kind, remains the total extra-capsular thyroidectomy, so as is used, when possible, for the surgical removal of whatever other tumour” [19]. he further emphasized in his work published after his death in 1956 entitled “Treatise on Clinical Therapeutic Surgery” that “Only an removal of this capacity justifies, in the face of a proven malignant tumour, surgical intervention, any other incomplete or partial demolition does nothing but accelerate the ready reoccurrences, even in a very short time” [20]. * Correspondence: cirocchiroberto@yahoo.it General and Emergency Surgical Unit. Department of Surgical Sciences, Radiology and Dentistry. University of Perugia, Perugia, Italy Full list of author information is available at the end of the article Cirocchi et al. World Journal of Surgical Oncology 2011, 9:89 http://www.wjso.com/content/9/1/89 WORLD JOURNAL OF SURGICAL ONCOLOGY