Can MARS regression be used for classification? I am dealing with a data set in which I have to classify between a diseased and a non-diseased individual. I was wondering if it is possible to adapt the MARS regression (Multivariate adaptive regression spline) to use it for classification tasks. Thank you very much and best regards.

Earth (generic name) is just a way to make nonlinear basis functions $f_i$. Once you have those basis functions, you can apply a link function $g$ for a GLM, such as logistic regression or probit regression.
$$
\text{EARTH: }
\mathbb E[Y\vert X] = \sum_{i=1}^k\beta_if_i(X)\\
\text{GLM EARTH: }
g(\mathbb E[Y\vert X]) = \sum_{i=1}^k\beta_if_i(X)
$$
