Synchronous primary sigmoid colon cancer and primary thyroid cancer followed by a malignant tumor of the kidney: Case report of multiple primary cancer and review of the literature

Synchronous multiple primary malignancies of clear cell renal cell carcinoma with sarcomatoid, thyroid carcinoma: a case report

Multiple primary malignant neoplasms (MPMNs) are defined as the presence of two or more malignancies with different histologies in the same patient. MPMNs are rare, accounting for fewer than 4% of all tumor cases. Depending on the time interval between the diagnosis of the different malignancies, they are classified as either simultaneous or metachronous MPMNs, with simultaneous being rarer in MPMNs. Here, we present a 63-year-old female patient presenting with multiple primary renal and thyroid carcinomas and discuss the risk factors, treatment options, and prognosis of rare dual carcinomas. We focus on managing multidisciplinary teams and selecting individualized treatment options to deliver valuable treatment strategies to patients.

Thyroid and renal cancers: A bidirectional association

There is a deep interrelation between the thyroid gland and the kidney parenchyma, with dysfunction of the first leading to significant changes in renal metabolism and vice versa. Given the recognition of cancer as a systemic disease, the raise of thyroid tumors and the common association of several malignancies, such as breast cancer, prostate cancer, colorectal cancer, and other, with an increased risk of kidney disease, public health alert for these conditions is warranted. A systematic review of the current evidence on the bidirectional relationship between thyroid and renal cancers was conducted including 18 studies, highlighting patient’s characteristics, histology, time for secondary malignancy to develop from the first diagnosis, treatment, and follow-up. A total of 776 patients were identified; median age was 64 years (range: 7–76 years). Obesity and family history were identified as the most common risk factors, and genetic susceptibility was suggested with a potential strong association with Cowden syndrome. Controversy on chemo and radiotherapy effects was found, as not all patients were previously exposed to these treatments. Men were more likely to develop kidney cancer after a primary thyroid malignancy, with 423/776 (54%) experiencing renal disease secondarily. Median time after the first malignancy was 5.2 years (range: 0–20 years). With the advancement of current oncological therapy, the prognosis for thyroid cancer patients has improved, although there has been a corresponding rise in the incidence of multiple secondary malignancy within the same population, particularly concerning the kidney. Surgery can achieve disease-free survival, if surveillance follow-up allows for an early localized form, where radical treatment is recommended.

Experimental Modeling of Multiple Primary Malignant Processes with One Tumor Suppressed by Another under Conditions of Primary Immunodeficiency

The phenomenon of multiple primary malignant tumors (MPMT) is characterized by the presence of several primary neoplasms in the same patient. An experimental model of MPMT with one dominating tumor was developed. Female BALB/c nude mice received simultaneous subcutaneous inoculation of Guerin's carcinoma (5×10⁵ tumor cells in 0.5 ml saline) and B16/F10 melanoma (0.5 ml suspension diluted 1:20 with saline). Control females received transplantation of either melanoma or carcinoma alone in the same doses and volumes. In animals with MPMT model, tumors appeared 3-fold faster than after isolated transplantation of melanoma or Guerin's carcinoma and were larger by 7.5 and 2.2 times, respectively; the survival of mice with MPMT was lower. Guerin's carcinoma in the MPMT model metastasized to melanoma and almost completely suppressed its growth. Thus, a MPMT model was created with carcinoma suppressing the malignant growth of melanoma.

Inhibition of circular RNA_0000285 prevents cell proliferation and induces apoptosis in thyroid cancer by sponging microRNA-654-3p

Thyroid cancer is derived from follicular or thyroid cells and has become the most prevalent malignant tumor of endocrine organs, with increased morbidity and mortality. Circular RNAs (circRNAs) are used as prognostic and predictive markers for different types of cancer. However, the role of circRNA_0000285 in thyroid cancer and its potential molecular mechanism remain unclear. The present study aimed to investigate the roles and underlying molecular mechanism of circRNA_0000285 in thyroid cancer to identify novel treatments for this disease. The target binding site of circRNA_0000285 and microRNA-654-3p (miR-654-3p) were predicted and confirmed via the dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Thyroid cancer cell viability and apoptosis were determined via the MTT assay and flow cytometric analysis, respectively, whereas the expression levels of circRNA_0000285 and miR-654-3p were determined via reverse transcription-quantitative PCR analysis. In addition, the protein expression levels of the apoptosis-associated proteins, Bax and B-cell lymphoma 2 (Bcl-2), were detected via western blotting. The results of the dual-luciferase reporter and RIP assays demonstrated that miR-654-3p directly targeted circRNA_0000285. The expression levels of circRNA_0000285 and miR-654-3p in thyroid cancer cells (TPC-1 and FTC133) were upregulated and downregulated, respectively. Knockdown of circRNA_0000285 via small interfering (si)RNA inhibited circRNA_0000285 levels and increased miR-654-3p levels. In addition, miR-654-3p expression decreased following transfection with miR-654-3p inhibitor. Functional experiments demonstrated that circRNA_0000285-siRNA decreased thyroid cancer cell proliferation, promoted cell apoptosis, enhanced Bax expression and suppressed Bcl-2 expression. All these effects were reversed following transfection with miR-654-3p inhibitor. Taken together, the results of the present study suggest that circRNA_0000285 plays a vital role in thyroid cancer progression by regulating miR-654-3p, which provides a potential therapeutic target for this disease.

Positron Emission Tomography With Fluorodeoxyglucose Incidental Detection of Colon Cancer in a Patient's Follow-Up for Nasopharyngeal Carcinoma During the COVID-19 Pandemic: A Case Report

Colorectal cancer (CRC) is a type of widespread, deadly malignancy that took thousands of lives around the globe. In the last two decades, CRC represented the most common cancer among men and ranked third among women in Saudi Arabia. Positron emission tomography with fluorodeoxyglucose (FDG-PET), can incidentally detect malignancy, as in our case, FDG-PET disclosed high abnormal FDG far away from the first primary malignancy. The current case is of a 65-year-old female who was following up on her nasopharyngeal carcinoma (first primary). During her last management, FDG-PET was requested to find any FDG uptake in the nasopharyngeal region; stunning FDG uptake was incidentally found at the ascending colon diagnosed as early-stage (pT2N0) colon cancer. Colonoscopy was done and India Ink was injected to facilitate localizing the mass during the laparoscopic removal of the tumor, which was delayed due to the pandemic of COVID-19. This took place in March 2020 at King Abdul-Aziz University Hospital in Jeddah.

Triple Metachronous Malignancies with Thyroid Involvement: A Brief Overview of Five Case Reports over 20 Years of Institutional Experience

Multiple primary malignant tumors are defined by the development of more than one malignancy in a single patient. These can be subdivided into synchronous or metachronous malignant tumors, depending on their time of appearance, relative to the first malignancy. Triple primary malignancies are a relatively rare occurrence in day-to-day practice and triple synchronous or metachronous carcinomas involving a thyroid localization are even less common. In this case series, we report our 20-year experience in diagnosing and managing five patients with triple malignant tumors with thyroid involvement.