Second Primary Cancers in Patients with Invasive and In Situ Squamous Cell Skin Carcinoma, Kaposi Sarcoma, and Merkel Cell Carcinoma: Role for Immune Mechanisms?

Decoding the mechanisms behind second primary cancers

Second Primary Cancers (SPCs) are defined as cancers that develop either simultaneously or metachronously in the same individual who has been diagnosed with and survived one primary cancer. SPCs exhibit a high incidence rate and represent the primary cause of mortality among survivors of first primary cancers. There is growing concern about the dangers of SPCs. This review summarizes recent studies on the mechanisms of SPCs, including the roles of genomic changes after first primary cancer (FPC) treatments, stromal cell phenotypic and metabolic changes, hormone levels and receptor expression, immunosuppression, aberrant gene methylation, EGFR signaling, and cell-free DNA in SPC development. This comprehensive analysis contributes to elucidating current research trends in SPC mechanisms and enhances our understanding of the underlying pathophysiology. Furthermore, potential applications of intratumoral microbes, single-cell multi-omics, and metabolomics in investigating SPC mechanisms are also discussed, providing new ideas for follow-up studies.

Merkel cell carcinoma overlapping Bowen's disease: two cases report and literature review

PURPOSE

Merkel cell carcinoma (MCC) is a rare neuroendocrine tumor of the skin, which mainly occurs in the sun exposed sites of white patients over 65 years, with a higher recurrence and metastasis rate. Clinically, MCC overlapping Bowen's disease (BD) is a very rare subtype of MCC. Few cases in the literature have been described and the management is not well defined. We summarize and update the epidemiology, clinical and histopathological features, metastasis characteristics, local recurrence rate and management of it by presenting two cases of MCC overlapping BD and reviewing the literature over the last 11 years.

DESIGN

We consulted databases from PubMed, ResearchGate and Google Scholar by MeSh "Merkel cell carcinoma" and "Bowen's disease", "Bowen disease" or "squamous cell carcinoma in situ", from January 2013 to December 2023 and reviewed the literatures. We reported two additional cases.

RESULTS

Total 13 cases of MCC overlapping BD were retrospectively analyzed, in whom mainly in elderly women over 70 years, the skin lesions were primarily located on the faces, followed by the extremities and trunk. Most of them were asymptomatic, firm, dark red nodules arising on rapidly growing red or dark brown patches, or presenting as isolated nodules. Dermoscopy evaluation was rarely performed in the pre-operative diagnostic setting. All cases were confirmed by histopathology and immunohistochemistry. The most definitive treatment was extended local excision, but local recurrences were common. Of the 13 cases, 4 cases experienced local or distant metastasis. One suffered from an in-transit recurrence of MCC on the ipsilateral leg after local excision and lymph node dissection, whose metastasis completely subsided after avelumab treatment and without recurrence or metastasis during 6 months of follow-up.

CONCLUSIONS

MCC overlapping BD is a very rare skin tumor mainly predisposed on the faces, with high misdiagnosis rate and recurrence rate. Advanced disease at diagnosis is a poor prognostic factor, suggesting that earlier detection may improve outcome. The acronym, AEIOUN, has been proposed to aid in clinical identification. Our reports and the literature review can provide a better awareness and management of it.

Updates on the diagnosis, current and future therapeutic options in Merkel-cell carcinoma

Merkel-cell carcinoma (MCC) is a rare and extremely aggressive nonmelanocytic cutaneous neuroendocrine carcinoma. Historically, it has been associated with limited therapy options and poor prognosis. While its incidence has been rising over the last two decades, recent discoveries and a better understanding of its pathogenesis, viral association and immunologic features have allowed for the emergence of new therapies. Surgical excision with or without radiotherapy remains the first-line therapy for primary lesions without evidence of metastatic disease. The majority of MCC cases are regrettably diagnosed at advanced stages and oftentimes require systemic therapy. There have been several significant advances in the treatment of MCC in the last decade. Among these have been the development of immune checkpoint inhibitors targeting the programmed death protein-1 (PD-1)/programmed death ligand-1 (PDL-1). Despite recent success of immunotherapy, nearly 50% of patients diagnosed with MCC still succumb to the disease. Fortunately, there has been a number of new targeted therapies that hold great promise. Among them are phosphatidylinositide-3kinase (Pl3K) inhibitors, adoptive T-cell immunotherapy, activated NK-92 cells infusions and therapeutic vaccines. Additional emerging therapeutic targets include cellular ubiquitin-specific processing protease 7 (Usp7) that restricts viral replication and IFN genes (STING), activation of which promotes an antitumor inflammatory response.

Second Primary Cancers After Gastric Cancer, and Gastric Cancer as Second Primary Cancer

Background

Second primary cancers (SPCs) are increasing, which may negatively influence patient survival. Gastric cancer (GC) has poor survival and when it is diagnosed as SPC it is often the cause of death. We wanted to analyze the risk of SPCs after GC and the risk of GC as SPC after any cancer. Such bidirectional analysis is important in relation to fatal cancers because SPCs may be under-reported in the short-term survival period.

Methods

Cancers were obtained from the Swedish Cancer Registry from years 1990 through 2015. Standardized incidence ratios (SIRs) were used to estimate bidirectional relative.

Results

We identified 23,137 GC patients who developed 1042 SPCs (4.5%); 2158 patients had GC as SPC. While the risk for three SPCs was increased after GC, seven first primary cancers were followed by an increased risk of GC as SPC, including esophageal, colorectal, bladder, squamous cell skin and breast cancers and non-Hodgkin lymphoma. Breast cancer, which was followed by a diagnosis of second GC, showed an excess of lobular histology.

Conclusion

Multiple primary cancers in the same individuals may signal genetic predisposition. Accordingly, the association of GC with breast cancer may be related to mutations in the CDH1 gene, and clustering of colorectal, small intestinal and bladder cancers could be related to Lynch syndrome. The third line of findings supports a contribution of immune dysfunction on the increased risk of GC as SPC after skin cancer and non-Hodgkin lymphoma. Early detection of GC in the risk groups could save lives.

Bladder and upper urinary tract cancers as first and second primary cancers

Background

Previous population‐based studies on second primary cancers (SPCs) in urothelial cancers have focused on known risk factors in bladder cancer patients without data on other urothelial sites of the renal pelvis or ureter.

Aims

To estimate sex‐specific risks for any SPCs after urothelial cancers, and in reverse order, for urothelial cancers as SPCs after any cancer. Such two‐way analysis may help interpret the results.

Methods

We employed standardized incidence ratios (SIRs) to estimate bidirectional relative risks of subsequent cancer associated with urothelial cancers. Patient data were obtained from the Swedish Cancer Registry from years 1990 through 2015.

Results

We identified 46 234 urinary bladder cancers (75% male), 940 ureteral cancers (60% male), and 2410 renal pelvic cancers (57% male). After male bladder cancer, SIRs significantly increased for 9 SPCs, most for ureteral (SIR 41.9) and renal pelvic (17.2) cancers. In the reversed order (bladder cancer as SPC), 10 individual FPCs were associated with an increased risk; highest associations were noted after renal pelvic (21.0) and ureteral (20.9) cancers. After female bladder cancer, SIRs of four SPCs were significantly increased, most for ureteral (87.8) and pelvic (35.7) cancers. Female bladder, ureteral, and pelvic cancers associated are with endometrial cancer.

Conclusions

The risks of recurrent urothelial cancers were very high, and, at most sites, female risks were twice over the male risks. Risks persisted often to follow‐up periods of >5 years, motivating an extended patient follow‐up. Lynch syndrome‐related cancers were associated with particularly female urothelial cancers, calling for clinical vigilance.

Second Primary Cancers After Kidney Cancers, and Kidney Cancers as Second Primary Cancers

Background

Second primary cancers (SPCs) are increasing due to improving survival in first primary cancers. Previous studies on SPCs in renal cell carcinoma (RCC) have focused on treatment and other risk factors, but data of RCC as an SPC are scarce.

Objective

In this study, we want to elucidate the risk for any SPC after RCC, and in reverse order, for RCC as an SPC after any cancer. We additionally consider how family histories influence the risks.

Design, setting, and participants

Patient data were obtained from the Swedish Cancer Registry from years 1990 through 2015, and family data were obtained from the Multigeneration Register.

Outcome measurements and statistical analysis

We employed standardized incidence ratios to estimate bidirectional relative risks of subsequent cancer associated with RCC.

Results and limitations

We identified 17 587 RCCs (60% in male patients). The highest increases for SPCs were observed for nervous system hemangioblastoma (HB; 26.8), adrenal (12.09) tumors, and renal pelvic cancer (6.32). In the reverse order, RCC as an SPC, nervous system HB (17.01), and adrenal tumors (15.34) were associated with the highest risks. Risks for many other sites (12 sites and subsites) were increased bidirectionally. For women, a total of seven sites and subsites were increased bidirectionally, and many were shared with men. The only significant sex difference in SPCs was the higher lung cancer risk in women (2.41) than in men (1.28). Patients with a family history of HBs or of prostate, colorectal and lung cancers showed high risks of these cancers as SPCs after RCC. Family history accounted for 30% of prostate cancers after RCC.

Conclusions

The bidirectional study design was able to suggest risk factors for SPCs and offered a clinical take-home message urging to consider strategies for early detection and prevention of SPCs. Readily available information on lifestyle (eg, smoking) and family history (eg, prostate cancer) may reveal targets for risk reduction with prognostic benefits.

Patient summary

Close to 10% of kidney cancer patients develop another cancer. The cause for these other cancers may not depend on kidney cancer.

Rate differences between first and second primary cancers may outline immune dysfunction as a key risk factor

Background

Many cancers are increased in immunosuppressed patients and evidence is accumulating that immune dysfunction may be a contributing risk factor for second primary cancers (SPCs). The aim of this study was to explore the potential influence of immune mechanisms in SPC.

Methods

We used the Swedish Cancer Registry (1990‐2015) to select 13 male and 14 female first primary cancers (FPCs) that are known to be related to immune suppression. We assessed relative risks (RRs) for any of these as concordant (same first and second cancer) and discordant FPC‐SPC pairs. Hierarchical clustering of significant RRs was performed for cancers as FPC and SPC.

Results

Concordant risks for SPCs were excessive in men and women for nasal (RRs 59.3 for men and 150.6 for women), tongue/mouth (51.7 and 100.8), and lip (32.4 and 61.2) cancers. Heatmaps showed that some cancers, such as skin cancer, tongue/mouth cancers, and non‐Hodgkin lymphoma had multiple bidirectional associations as FPC and SPC. Nasal cancer and chronic lymphocytic leukemia had associations mainly as FPC while liver and kidney cancers showed most associations as SPC.

Conclusions

Immune dysfunction may be a plausible contributing factor for most of the associations, which calls for experimental verification.

Incidence Differences Between First Primary Cancers and Second Primary Cancers Following Skin Squamous Cell Carcinoma as Etiological Clues

Background

Most literature on second primary cancers (SPCs) focuses on possible factors, which may increase the risk of these cancers, and little attention has been paid for the overall incidence differences between first primary cancers (FPCs) and same SPCs. We wanted to compare the incidence rates for all common cancers when these were diagnosed as FPCs and SPCs after invasive and in situ squamous cell carcinoma (SCC) of the skin, which are usually treated by surgery only.

Methods

Cancers were identified from the Swedish Cancer Registry from the years 1990 through to 2015, and they included, in addition to skin cancers, 20 male cancers totaling 484,850 patients and 22 female cancers totaling 452,909 patients. Standardized incidence rates and relative risks (RRs) were calculated for sex-specific common cancers as FPC and as SPC after skin SCC. Spearman rank correlations were used in the analysis of incidence ranking of FPC and SPC.

Results

Of total, 29,061 men and 23,533 women developed invasive SCC and 27,842 men and 36,383 women in situ SCC. The total number of 20 other male cancers was 484,850 and of 22 female cancers it was 452,909. Rank correlations ranged from 0.90 to 0.96 (P~5×10^-6), indicating that overall skin SCC did not interfere with SPC formation. The exceptions were increased SPC risks for melanoma, sharing risk factors with skin SCC, and non-Hodgkin and Hodgkin lymphoma, and cancers of the upper aerodigestive tract, connective tissue, and male and female genitals suggesting contribution by skin cancer initiated immune dysfunction.

Conclusion

The incidence ranking of SPCs after skin cancers largely follows the incidence ranking of FPCs indicating that overall skin SCC does not greatly interfere with the intrinsic carcinogenic process. The main deviations in incidence between FPC and SPC appeared to be due to shared risk factors or immunological processes promoting immune responsive cancer types.