Hemophilia is a rare genetic bleeding disorder affecting the blood’s clotting ability. A deficiency causes the disease in one of the clotting factors in the blood, which can lead to prolonged and spontaneous bleeding [
9]. Except for HCV-associated hepatocellular carcinomas and HIV-associated lymphomas, mortality rates for cancer in mild haemophilia patients seem the same as in the general population [13]. Indeed, the in vitro and in vivo findings that severe haemophilia protects against cancer development have not been confirmed for mild haemophilia [14]. Darby et al. reported cause-specific mortality from 1977 to 1998 in males in the United Kingdom with haemophilia A or B who were not infected with HIV compared with national mortality distinguished by severe and moderate/mild haemophile. The authors noted that mortality from liver cancer and Hodgkin’s disease was increased compared with mortality in the general population (standardized mortality ratio of 13.51 and 4.95, respectively). The standardized mortality ratio in severe cases is 4.98, and in moderate/mild cases, it is 4.95. Regarding liver cancer, the standardized mortality ratio in the severe group is 32.89 and in the moderate/mild 13.51. The presence of cancer in acquired haemophilia compared to patients who do not have an associated cancer is associated with increased all-cause mortality (OR: 2.76, 95% CI: 1.38–5.50) [39]. In-vitro investigations indicate that factor VIII may have a crucial role in the initial blood-borne phase of the metastatic process. In fact, in an experimental study involving murine (B16F10 murine melanoma cell line), Brüggemann et al. [
10] showed that congenital prothrombotic disorders, such as factor V Leiden, facilitate the metastatic potential of cancer, while congenital bleeding tendencies, like haemophilia A, significantly reduce metastasis. These findings align with those previously reported by Langer and co-authors [
11], who illustrated that administering factor VIII replacement therapy to hemophilic mice enhances the formation of lung metastases. Reduced production of thrombin, a potent cancer promoter, could potentially account for the lower incidence of cancer in haemophiliac patients [
12]. Survival in patients with haemophilia (PWH) can depend on various factors, including the type and stage of cancer, the severity of haemophilia, and the treatments received [
13].
Between 1970 and the early 1980s, mortality rates among PWH significantly decreased due to the widespread availability of clotting factor replacement products and the establishment of specialised haemophilia treatment centers (HTCs) that improved medical care [
14]. The emergence of malignancies is one of the important causes of morbidity and mortality in PWH. Several studies have reported a higher prevalence of cancer in PWH than in the general population, where PWH is diagnosed with cancers at a much younger age [
13,
15,
16,
17,
18,
19]. In the past decade, literature mainly focused on the epidemiology and outcome of blood-borne cancers in the haemophilia patient group, as the incidence of Hepatitis B virus (HBV), Hepatitis C virus (HCV), and HIV infection were high among them [
11,
20]. However, with the introduction of recombinant clotting factor concentrates (CFCs), physicians pay attention to non-virus-related malignancies. However, there is limited data on the epidemiology of non-virus-related malignancy in PWH [
20,
21,
22]. Patients with haemophilia may have an increased risk of developing certain types of cancer, such as liver cancer and Hodgkin’s disease [
15,36], because of the chronic inflammation and cell damage that can occur due to repeated bleeding episodes and replacement therapy. Soucie et al. in 2000 found that cancer unrelated to HIV or liver caused 2.2 times more deaths than the standard mortality rate [
14]. Similarly, Miesbach et al. in 2009 discovered that older adults with HIV had a four times higher cancer prevalence than the age-matched general population, excluding hepatocellular carcinoma (HCC) [
22]. However, Plug et al.’s research suggested that excluding HCC did not increase malignancy-related deaths among people with HIV [
23]. Shetty et al. conclude that the literature on an increase in non-viral malignancies is contradictory. There is an increase in HCC incidence in the overall haemophilia population, and most cases are due to HCV infection. As HCV infection is the most crucial risk factor for HCC in the haemophilia population, regular screening for liver diseases is necessary, and a multidisciplinary approach is required to provide optimal therapeutic options [
24]. Because hepatocellular carcinoma (HCC) appears to be an important cause of increased mortality in the elderly haemophiliac population, we report a summary table (
Table 1) of all studies describing mortality from this type of cancer in haemophilia patients.
Nonetheless, most of the literature data pertains to overall cancer-related mortality compared to the general population. Thus, studies should analyse the incidence of virally negative haemophilia patients. Walker et al. reported that cancer-related deaths among HIV-negative PWH in Canada were lower than expected when it excluded liver cancer and lymphoma [
25]. Furthermore, a systematic review by Miesbach et al. demonstrated that excluding HIV and hepatoma decreased the standard mortality rate for people with HIV. [
21]. While these studies provide valuable information, they are limited by small sample sizes. Additionally, differences in the timing of the studies could contribute to variations in cancer prevalence and outcomes, which the widespread introduction of CFCs and modern comprehensive haemophilia care may influence. Huang et al. conducted a nationwide population-based analysis of the occurrence and survival of cancer in PWH between 1997 and 2010 [
13]. The study showed that PWH had a survival time similar to that of the general population after acquiring cancer. However, long-term treatment with CFCs can intensify thrombin-induced metastases, or the replacement dosage may be too low to generate such an effect [
13]. The incidence and survival of cancers among PWH in Taiwan are increasingly affected by age-related diseases such as cancer. Huang et al. analyzed the data on 1,054 PWH compared with 10,540 age- and gender-matched healthy individuals from the general population. The study found that PWH had a higher incidence of cancer, including hepatocellular carcinoma, than the general population. PWH who developed cancer were younger and had fewer comorbidities at diagnosis, but survival rates were as in the general population [
13]. The challenges in haemophilia care have evolved. In the past, complications due to contaminated blood supply were the primary concern [
25,
26]. Still, with the availability of recombinant coagulation concentrates, age-related comorbidities such as malignancies, cardiovascular events, and diabetes have become important causes of morbidity and mortality [
15,
27,
28,
29]. Previous studies focused on blood-borne cancers [
1,
30,
31], but more recent research has explored non-virus-related malignancies [
21,
22]. Animal models suggest that coagulation factors may affect cancer outcomes, with haemophilia possibly inhibiting metastasis [
11]. The study also found that the prevalence of cancers among PWH was higher than in the general population, even after excluding patients with HIV or HCV infection [
13]. In
1979, Forman conducted the most extensive study on cancer epidemiology in patients with inherited bleeding disorders, which identified 61 cases of cancer out of an estimated population of 10,500 patients. The primary site of cancer in haemophilia patients was similar to that of an age and sex-matched population. There was no evidence of a change in the onset of metastatic disease in these patients compared to individuals with cancer but without coagulopathy [
32]. Darby et al. found that mortality from liver cancer was higher in hemophilic men in the UK treated with blood products contaminated with hepatitis C, with a 25-year cumulative risk of death from liver cancer of 0.37%, significantly higher than the expected rate of 0.03% from national mortality rates. The study also found that lymphoma cases in the UK haemophilia population between 1978 and 1999 mainly occurred in HIV-positive patients [
15]. In the Netherlands, a prospective cohort study found that deaths from malignant neoplasms accounted for 22% of deaths in the Dutch haemophilia population from 1992–
2001, with a standardised mortality ratio (SMR) of 1.5. The study also showed a highly increased risk of death from hepatocellular carcinoma [
23]. In Canada, liver cancer or lymphoma deaths have increased significantly among HIV-positive individuals compared with HIV-negative individuals. Moreover, deaths due to all cancers were not increased in the population [
25]. Soucie and colleagues found that a small percentage of deaths among haemophiliacs in six US states during 1993–1995 was attributable to non-HIV- or liver-related cancers with a standardised mortality ratio of 2.2 [
14]. Conversely, Triemstra and colleagues found no excess mortality from cancer in a cohort of Dutch haemophiliacs from 1986 to 1992 [
33]. More recently, Darby and colleagues found that mortality from liver cancer and Hodgkin’s disease was substantially increased compared with mortality in general in the UK. There was no evidence of increased mortality from other cancers [
15]. Liver cancer and lymphoma are more prevalent in haemophiliacs infected with HCV or HIV. Still, there is no evidence of an increased incidence of other malignancies in patients with haemophilia compared to the general population [
34]. While the hypothesis that haemophilia may offer protection against diseases like cancer is intriguing, it remains unproven and needs further investigation [
34]. The available data on the clinical management of cancer in haemophiliacs is limited, with most studies based on anecdotal case reports [
35]. However, a retrospective survey conducted by the Association of Haemophilia Centres (AICE) found that non-virus-related cancers were less common in severe haemophilia patients than in those with milder forms of the disorder [
36]. Haemophilia is not a direct risk factor for cancer, but the treatments for haemophilia can increase the risk. In particular, the author suggests that blood transfusions and clotting factor replacement therapy may be associated with increased cancer risk. This concern has been raised in previous research, which has suggested that exposure to blood products may increase the risk of viral infections that can contribute to cancer development [
37].