Searching in order to detect an association of rheumatic syndromes in cancer patients (with a high prevalence of these complications) can be helpful to detect the underlying neoplasia. The association of malignancies and their RM is a complex issue. Occasionally rheumatologic syndromes are associated with symptoms of an underlying malignancy. Higher age of onset, more prominent systemic manifestations, atypical presentation of the disease, unresponsiveness to steroids or other classic therapies may suggest a paraneoplastic process (
1,
2). Some specific rheumatologic diseases are associated with higher risks of malignancy (
3,
4). On the other hand, some malignancies show paraneoplastic rheumatologic manifestations and may be presented with articular, muscular or soft tissue symptoms (
3,
5).
In this study there were not any significant differences between genders for the presence of RM and age. The highest and lowest numbers of RM in the females was seen with fibromyalgia (46.9%) and hypertrophic osteoarthropathy (HOA) (0%) respectively. However, there was a significant difference based on age for the presence of RM. The most representative age group was 61 - 70 years old. The incidence of fibromyalgia has been seen in the all age group patients under 70 years old. Most rheumatologic manifestation was seen with fibromyalgia (34 patients, 30 females and 4 males, 53.1%).
Agarwala in 1996 reported that paraneoplastic syndromes are seen in less than 15 percent of malignancies (
6). In this study, the presence of paraneoplastic syndromes in the patients based on type of solid tumors showed significant differences.
In our study, presence of RM that was based on cancer type, was as follows from most to least: breast, lung, colon, ovary, liver, bone, testis and prostate. In a study by Naschitz et al. in 1997 it was shown that atypical manifestations of polymyalgia rheumatic are associated with underlying malignancy. kidney, colon, and multiple myeloma were the most common associated malignancies (
10). Gonzalez-Gay et al. (
9) in 2000 have reported that the prevalence of vasculitis in patients with underlying malignancy was around 8%. Gheita et al., 2009 in a study at Egypt have shown that 45 out of 60 patients which were suffering from solid tumors show myalgia, arthralgia, polyarthritis, flexor tenosynovitis, fibromyalgia syndrome, frozen shoulder and hypertrophic osteoarthropathy and 15 patients had hematologic malignancies (
7). While in our study, the presence of RM was as follows: fibromyalgia (53.1%), arthropathy (15.6%), polymyalgia rheumatic (10.9%), Raynaud’s phenomenon (9.4%), frozen shoulder (9.4%) and hypertrophic osteoarthropathy (1.6%,
Figure 1). Approximately similar results have been reported by Akkaya et al. which shows higher frequency of fibromyalgia in the operated breast cancer patients (
11). In the present study, there was no significant difference between the RM and the stage of disease among the patients, but most reports have been seen in stage 4 and 3.
Taken together our results and the results from the Ashouri and Daikh suggests that rheumatic disease might be a kind of component of the spectrum of paraneoplastic manifestations (
12).
From the findings, it seems that the most rheumatologic manifestations are gender dependent. The results of this study can be used as a tool for more effective treatment and monitoring clinical studies of RM in patients with solid tumors especially fibromyalgia and breast cancer. It may suggest that: a prospective study for monitoring the patients and their rheumatologic manifestations is needed.
5.1. Suggestions
1- According to the possibility of asynchronous signs of paraneoplastic syndrome, a prospective study is needed.
2- The available studies for PRM screening are not enough and more studies are needed.
3- Rheumatologists must work closely with oncologists to identify the association of RM with malignancy.