The statistical properties of quantum transport through a chaotic cavity are encoded in the traces T n =Tr͓͑tt † ͒ n ͔, where t is the transmission matrix. Within the random matrix theory approach, these traces are random variables whose probability distribution depends on the symmetries of the system. For the case of broken time-reversal symmetry, we use generalizations of Selberg's integral and the theory of symmetric polynomials to present explicit closed expressions for the average value, and for the variance of T n for all n. In particular, this provides the charge cumulants ͗͗Q n ͘͘ of all orders. We also compute the moments ͗g n ͘ of the conductance g = T 1 . All the results obtained are exact, i.e., they are valid for arbitrary numbers of open channels.