Hyaluronic acid (HA), also named hyaluronan, is an omnipresent component of the tissue microenvironment is extensively used to formulate targeted drug delivery systems for cancer. Although HA itself has pivotal influences in various cancers, its calibers are somewhat neglected when using it as delivering platform to treat cancer. In the last decade, multiple studies revealed roles of HA in cancer cell proliferation, invasion, apoptosis, and dormancy through pathways like cluster of differentiation 44 (CD44), mitogen-activated protein kinase-extracellular signal-regulated kinase (MAPK/ERK), P³⁸, and nuclear factor kappa-light chain-enhancer of activated B cells (NFκB). A more fascinating fact is that the distinct molecular weight (MW) of HA exerts disparate effects on the same type of cancer. Its overwhelming use in cancer therapy and other therapeutic products make collective research on the sundry impact of it on various types of cancer, an essential aspect to be considered in all of these domains. Even the development of new therapies against cancer needed meticulous studies on HA because of its divergence of activity based on molecular MW. This review will provide painstaking insight into the extracellular and intracellular bioactivity of HA, its modified forms, and its MW in cancers, which may improve the management of cancer.

透明质酸（HA），也称为乙酰透明质酸，是组织微环境中无处不在的成分，广泛用于配制癌症靶向药物递送系统。尽管HA本身对多种癌症具有关键影响，但在将其用作治疗癌症的传递平台时，其能力却有些被忽视。在过去的十年中，多项研究揭示了HA通过分化簇44（CD44）、丝裂原激活蛋白激酶-细胞外信号调节激酶（MAPK/ERK）等途径在癌细胞增殖、侵袭、凋亡和休眠中的作用，第³⁸页，以及活化 B 细胞的核因子 kappa-轻链增强子 (NFκB)。一个更有趣的事实是，HA 的不同分子量 (MW) 对同一类型的癌症产生不同的影响。它在癌症治疗和其他治疗产品中的大量使用使得人们对其对各种类型癌症的各种影响进行集体研究，这是所有这些领域中需要考虑的一个重要方面。即使是针对癌症的新疗法的开发也需要对 HA 进行细致的研究，因为它的活性根据分子分子量而存在差异。这篇综述将深入了解 HA 的细胞外和细胞内生物活性、其修饰形式及其在癌症中的分子量，这可能会改善癌症的治疗。