Cancers of the head and neck are unusual in that appears to have been little,
if any, improvement in survival rates over recent decades.
头部及颈部的癌症怎么了然后近几十年的存活率有增加?

头颈部癌症最近数十年的存活率似乎没什么/几乎没有改善，这种情况不寻常。 (little)似乎即使有改善也微乎其微

appears 前面少一个 there

两位大感谢!!