Respected Editor,

We read with interest the article on the frequency of gynecological malignancies in a tertiary care center in southern Pakistan. We noted that ovarian cancer constituted almost 50%, whereas cancer of the cervix constituted a mere 9% of all gynecological cancers [1]. The authors note that “results are different in comparison to a western population …., thus more research is warranted regarding different factors…”. Clearly, these results are at variance, not only with the western population but also with the figures published by the Globocan. For example, cancer of the uterine cervix is the 2nd most common cancer in women and the most common cancer in 23 out of 185 countries worldwide [2].

Afridi and Zahid reported on the data from a hospital- based registry. Whereas the hospital-based registries extract data from all patients diagnosed or treated at a single institution, there are limitations, as the data are not generalizable to the community, region or country [3]. The focus of a hospital-based registry is on clinical care and serves important purposes such as clinical audits, reporting outcomes, and allocating hospital resources, in addition to learning and teaching the research methods. On the other hand, population-based or multi-institution registries provide information on the epidemiology, monitor cancer trends, help to devise awareness, prevention, and screening efforts, and to prioritize health resource allocations in the region or the country.

This very important paper draws attention to several points. Firstly, whereas, there may be actual variation in the geographic distribution of various gynecological cancers in southern Pakistan, one reason for the discrepancy may be the referral pattern. The vast majority of cervical cancers are diagnosed as stage II- IVA, where the standard-of-care treatment is chemo- radiotherapy. It is plausible to think, that if a hospital or cancer treatment center does not have an on-site comprehensive radiotherapy facility, then patients may not be referred to this hospital or center.

Secondly, data from a population-based registry from Karachi and southern Pakistan identified cervical cancer to constitute 4.1% of all cancers amongst women, which makes cervical cancer not one of the most common cancers in women in Pakistan [4]. However, the data, at least 20 years old, were based on pathology reports from the hospitals using the ICD-02 version. Worldwide cervical cancer is the 4th most frequently diagnosed cancer and the 4th leading cause of cancer death in women, with more than half-a-million new cases and more than 342,000 deaths worldwide. It accounts for the leading cause of cancer death in 36 countries, with the vast majority of these countries being low on the human development index (HDI), such as those in South- Eastern Asia, and sub-Saharan Africa [2].

Thirdly, ovarian cancer constituted 4.2% of all cancers amongst women, i.e. 0.1% more than cancer of the cervix in the Karachi registry [4]. This contrasts with the paper by Afridi and Zahid, where ovarian cancer is 5 times more common than cervical cancer. There are no recent population-based registry data or information, and hence it is difficult to conclude the actual population- based incidence of different gynecological cancers in Pakistan.

Finally, gynecological cancers constitute the 5th most common form of cancer, behind lung, breast, prostate, and colorectal cancers. Whereas there were an estimated 19.3 million new cases worldwide in 2020, the corresponding numbers are likely to increase to 28.4 million new cancer cases by 2040, with a larger increase in developing compared to developed countries. Due to demographic changes, such as aging, increasing risk factors (including infections, environmental factors, and a growing economy), the number of all cancers, together with gynecological cancer, is likely to increase alarmingly over the next few years in Pakistan.

It is imperative that an estimate of the burden of disease and types of cancer be made in Pakistan, or at least in different provinces. If the aim is to reduce the morbidity and mortality from cancer and to improve the quality

of life of cancer survivors, then efforts for prevention,

*Corresponding author: Ana Paula Galerani-Lopes, Department of Radiation Oncology, Sultan Qaboos Comprehensive Cancer Care and Research Center, Muscat, Oman; Email: agalerani@gmail.com

Received: June 17, 2022; Revised: August 17, 2022; Accepted: August 28, 2022 DOI: https://doi.org/10.37184/lnjcc.2789-0112.3.13

screening and early detection, resource allocation for diagnosis and staging, treatment, palliative care, and survivorship issues can be drawn objectively only in the presence of realistic data from large registries [5]. In

the absence of a national registry, cumulative data from multi-institutional registries may help to bridge the gap to a large extent. The paper by Afridi and Zahid may be the first step in the right direction.

CONFLICT OF INTEREST

The authors declare no conflicts of interest.

ACKNOWLEDGEMENTS

Declared none.

REFERENCES

1. Afridi HK, Zahid NA. Frequency of gynecological malignancies in a tertiary care centre in Karachi, Pakistan. Liaquat Natl J Cancer Care 2021; 3(1): 6-9

2. Sung H, Ferlay J, Siegel RL, et al. Global cancer statistics 2020: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2021; 71(3): 209-49.

3. Hospital-Based Registries. https://www.training.seer .cancer.gov/ registration/types/hospital.html. Accessed on June 12, 2022.

4. Bhurgri Y. Karachi Cancer Registry data – implications for the National Cancer Control Program of Pakistan. Asian Pacific J Cancer Prev 2004; 5: 77-82.

5. Parkin DM. The role of cancer registries in cancer control. Int J Clin Oncol 2008; 13(2): 102-11.