This population-based research revealed the clinicopathological features as well as survival of patients with cervical AC.Cervical AC constitutes only approximately 20%-25% of all cervical carcinomas2,3. AC is the second most common primary cervical cancer, secondly only to SCC 22.Previous studies predominantly enrolling patients with SCC have provided most of our knowledge about the treatment of cervical cancer23,24. However, the different outcomes for AC have been rarely reported. Furthermore, prospective studies have not focused on the treatment of AC as the only histology. Consequently, our understanding of the natural history, prognosis factors and optimal management of cervical AC is limited 25. For this purpose, by including a total of 3102 cervical AC patients, we aimed atdescribing the clinicopathological features and treatment, as well as examining prognostic indicators for cervical AC.
Depth of cervical invasion, tumor size, FIGO stage, nodal status 26,27, tumor grade and patient age28,29 were the most widely studied clinicopathological parameters for cervical AC. Although these studies are most based on small sample, single center retrospective studies, the results are basically consistent with ours. In addition, we also found that marital status is an independent prognostic factor for cervical AC.
The same therapeutic strategy is recommended for SCC and AC according to the present guidelines. Nevertheless, there have been no consistent data concerning the therapeutic efficacy in diﬀerent histological classification7. Surgery and radiotherapy are recommended as the primary therapeutic regimes for early-stage cervical cancer in accordance with NCCN guidelines 8. In addition, the 5-year OS rates for stage IA1 and stage IA2 lesions were 96.5% and 99.4% for radical hysterectomy, 96.6% and 100% for local excision, 98.4% and 96.9% for simple hysterectomy in a study enrolling 1567 patients with cervical AC30. Our study also found that surgery is an independent favorable prognostic factor.
Radiotherapy is an alternative option for patients not fit for surgery or who refuse surgery. For patients with stage IB2-IVA cervical cancer, concurrent cisplatin based-chemoradiotherapy plus brachytherapy is the standard therapeutic regimen7. Our study found that for patients without surgery, radiotherapy and chemotherapy can bring significant survival benefits. However, in terms of tumor stage, only patients with stage III can gain significant survival benefits from radiotherapy.The worse efficacy of cervical AC is possibly caused by insensitivity of radiotherapy. Cervical AC patients have been reported to have poorer complete response (CR) as well as local control rates, therefore requiring longer time to obtain CR than SCC populations following CCRT or definitive radiotherapy23,31,32. Similarly, local failure is also more common in cervical AC patients. In addition, Hu revealed higher probability of distant failure in AC patients10. In consideration of poor outcomes of patients with cervical AC, more effective protocols are required for these patients.Adjuvant chemotherapy or neoadjuvant is a possible strategy. According to a Chinese clinical trial, 880 patients with FIGO stage IIB-IVA cervical AC were randomly assigned to receive only CCRT or CCRT with one cycle of neoadjuvant chemotherapy and two cycles of consolidation chemotherapy. Subsequently, patients treated by CCRT along with chemotherapy had better OS, DFS and local control after a median follow-up of 60 months. The above outcomes implicate that combined CCRT and chemotherapy is promising to enhance the survival of patients with cervical AC33.
The NCI-supported SEER database is the most authoritative and largest source for tumor incidence and survival. The large-scale, publicly available SEER dataset can be reliably used to guide anti-cervical AC therapy.As far as we know, our research includes the largest subjects to investigate prognostic parameters for cervical AC in the past ten years. Inevitably, there are also several limitations in our study. Firstly, selection bias and the effects of inaccessible variables from the SEER dataset are unavoidable due to the nonrandomized nature of our research13,34; Secondly, information on human papilloma virus 18 subtype7,35 were inaccessible from SEER database, which are considered as valuable indicators for survival of cervical cancer. Thirdly, SEER fails to provide all data to completely address our hypothesis, such as detailed information on chemotherapy and radiotherapy. Nevertheless, the currently accessible information from SEER database could fit our objectives. While the above-mentioned issues should be further investigated.