If you have a Photography plan, that plan does not exist as a monthly plan. But it's highly discounted, so you will not gain much by cancelling. What you can do is paying upfront for a year, and you will get even a higher reduction.
Cancelling an annual plan will get you to pay early cancellation fees of half of the remaining due. You will need really to calculate your gain then. If you have a Lightroom plan (not the Lightroom Classic plan), you will in addition use cloud space. You can't cancel that, without saving your cloud data locally. It can be a laborious operation to restore that afterwards. It simply does not make sense.
ABAMBO | Hard- and Software Engineer | Photographer