Cancer is one of the world's most serious health problems and the top cause of mortality today. S. variolaris is a valuable sea creature that has long been used as a folk medicine to cure and prevent ailments. A subcritical water extraction was used method to obtain crude extract from spikes of S. variolaris. The extract had shown antiproliferative effect in HeLa cells with an IC50 of 723.1 ± 9.73 µg/ml, but no toxicity in HEK293. Westernblot was used to detect protein expression; Bax, caspase-8, and IκBα were increased, whereas IKKα and p-NFκB-65(Ser 536) were downregulated. RNA/mRNA expression was revealed by RT-qPCR, and fold changes of caspase-3, cytochrome-c, Bax, Apaf-1, caspase-9, and Bak genes’ expression were raised. Using gel electrophoresis, the treatment groups showed more DNA fragmentation than the control group. GC-MS was used to identify the components in the crude extract; anticancer activity could be attributed to dodecanoic acid, hexadecanoic acid, and tetradecanoic acid content. In conclusion, these results showed the potential use of the crude extract of a spike from S. variolaris with anticancer activity against cervical cancer.