Background: Although clinically evident metastases of nonthyroid malignancies (NTMs) to the thyroid gland are uncommon, it is important to suspect them in patients who present with a new thyroid mass and a history, however far back, of prior malignancy. In fact, metastases from NTMs to the thyroid gland have been reported in 1.4%–3% of all patients who have surgery for suspected cancer in the thyroid gland. Here we review the literature over the last decade regarding this topic. Summary: Based on recent literature, the most common NTMs that metastasize to the thyroid gland are renal cell (48.1%), colorectal (10.4%), lung (8.3%), and breast carcinoma (7.8%), and sarcoma (4.0%). Metastases of NTMs to the thyroid are more common in women than men (female to male ratio=1.4 to 1) and in nodular thyroid glands (44.2%). The mean and median intervals between diagnosing NTMs and their metastases to thyroid gland are 69.9 and 53 months, respectively. In 20% of cases the diagnosis of the NTM and its metastases to the thyroid was synchronous. Recent reports indicate that there is a higher frequency of sarcoma metastasizing to the thyroid gland than reported in prior years. Fine-needle aspiration biopsy (FNAB) of thyroid masses is useful in diagnosis of thyroid metastases. However, this requires information about the NTM so that the proper antibodies can be used for immunohistochemical analysis; therefore it is of lesser utility if the NTM is occult. In patients with preexisting thyroid pathology the FNAB diagnosis can be more difficult due to more than one lesion being present. Conclusions: It is important to keep in mind that the thyroid gland can be a site of metastases for a variety of tumors when evaluating a thyroid nodule, especially in a patient with a prior history of malignancy. In patients with thyroid lesions and a history of malignant disease, regardless of time elapsed since the initial diagnosis of the primary neoplasm, disease recurrence or progression of malignancy must be considered until proven otherwise.

Background: Fluorescence-guided surgery (FGS) can enable successful cancer surgery where bright-light surgery often cannot. There are three important issues for FGS going forward toward the clinic: (a) proper tumor labeling, (b) a simple portable imaging system for the operating room, and (c) patient-like mouse models in which to develop the technology. The present report addresses all three. Materials and Methods: Patient colon tumors were initially established subcutaneously in nonobese diabetic (NOD)/severe combined immune deficiency (SCID) mice immediately after surgery. The tumors were then harvested from NOD/SCID mice and passed orthotopically in nude mice to make patient-derived orthotopic xenograft (PDOX) models. Eight weeks after orthotopic implantation, a monoclonal anti-carcinoembryonic antigen (CEA) antibody conjugated with AlexaFluor^® 488 (Molecular Probes Inc., Eugene, OR) was delivered to the PDOX models as a single intravenous dose 24 hours before laparotomy. A hand-held portable fluorescence imaging device was used. Results: The primary tumor was clearly visible at laparotomy with the portable fluorescence imaging system. Frozen section microscopy of the resected specimen demonstrated that the anti-CEA antibody selectively labeled cancer cells in the colon cancer PDOX. The tumor was completely resected under fluorescence navigation. Histologic evaluation of the resected specimen demonstrated that cancer cells were not present in the margins, indicating successful tumor resection. The FGS animals remained tumor free for over 6 months. Conclusions: The results of the present report indicate that FGS using a fluorophore-conjugated anti-CEA antibody and portable imaging system improves efficacy of resection for CEA-positive colorectal cancer. These data provide the basis for clinical trials.

Age at diagnosis is incorporated into all relevant staging systems for differentiated thyroid carcinoma (DTC). There is growing evidence that a specific age cutoff may not be ideal for accurate risk stratification. We sought to evaluate the interplay between age and oncologic variables in patients with DTC using the largest cohort to date. The Surveillance, Epidemiology, and End RESULTS (SEER) database was queried to identify patients with DTC as their only malignancy for the period 1973 to 2009. Multivariate analyses using a range of age cutoffs and age subgroupings were utilized in order to search for an optimal age that would provide the most significant risk stratification between young and old patients. The primary outcome was disease-specific survival (DSS) and covariates included: age, race, sex, tumor/nodal/metastasis (TNM) stage, decade of diagnosis, and radioactive iodine therapy. A total of 85,740 patients were identified. Seventy-six percent of patients were American Joint Committee on Cancer (AJCC) stage I, 8% were stage II, 7% were stage III, and 8% were stage IV. Age over 45 years (hazard ratio [HR] 19.2, p<0.001) and metastatic disease (HR 13.1, p<0.001) were the strongest predictors of DSS. Other factors that significantly predicted DSS included: not receiving radioactive iodine (RAI; HR 1.3, p=0.002), T3 (HR 2.6, p<0.001), and T4 disease (HR 3.3, p<0.001), and nodal spread (HR 2.6 to 3.3, p<0.001). Female sex showed a significant protective effect (HR 0.7, p=0.001). Adjusting the age-group cutoff from 25 to 55 years showed consistently high HRs for advanced age, without a distinct change at any point. Comparing HRs for T, N, and M stage between young and old patient subgroups showed that advanced disease increased the risk for DSS regardless of age, and was oftentimes a worse prognosticator in young patient groups. The contribution of age at diagnosis to a patient's DSS is considerable, but there is no age cutoff that affords any unique risk-stratification in patients with DTC.