No health maintenance organization under this chapter may refuse coverage or cancel or decline coverage solely because of a mastectomy or lumpectomy performed on the insured or prospective insured more than five years previously. The amount of benefits payable, or any term, rate, condition, or type of coverage shall not be restricted, modified, excluded, increased, or reduced solely on the basis of a mastectomy or lumpectomy performed on the insured or prospective insured more than five years previously.